Atlantic slave trade

The Atlantic slave trade developed after trade contacts were established between the "Old World" (Afro-Eurasia) and "New World" (the Americas). The ocean currents and prevailing winds of the Atlantic represented a barrier to return travel for seafarers who did not understand their pattern, whilst those with sufficient knowledge could use them as a tool to assist them. In the 15th century, European developments in seafaring technologies produced multi-masted sailing vessels with centre-line rudders, replacing the medieval cog and the Mediterranean round ship. This led to vessels more suited to Atlantic seafaring. Between 1600 and 1800, approximately 300,000 sailors engaged in the slave trade visited West Africa. In doing so, they came into contact with societies along the West African coast and in the Americas which they had never previously encountered. Pierre Chaunu termed the consequences of European navigation désenclavement, with it marking an end of isolation for some societies and an increase in inter-societal contact in maritime regions.

Historian John Thornton noted, "technical and geographical factors combined to make Europeans the most likely people to explore the Atlantic and develop its commerce". He identified these as being the drive to find profitable commercial opportunities outside Europe. There was the desire to create an alternative trade network to that controlled by the Muslim Ottoman Empire, which was viewed as a commercial, political and religious threat to European Christendom. European traders wanted to trade for gold, which could be found in West Africa, and find a maritime route to "the Indies" (India), where they could trade luxury goods such as spices, without having to obtain them from Islamic traders.

European overseas expansion led to contact between the Old and New Worlds, producing the Columbian exchange named after Christopher Columbus. It started the global silver trade from the 16th to 18th centuries, and involved the transfer of goods unique to one hemisphere to the other. Europeans brought cattle, horses, pigs, sheep, and chickens to the New World, and from the New World Europeans received turkeys, tobacco, potatoes, tomatoes, and maize. Other commodities becoming important in trade were the sugarcane, coffee, and cotton crops of the Americas, along with their gold and silver.

During the first wave of European colonization, although many Atlantic naval explorations were led by the Iberian conquistadors, members of many European nationalities were involved, including from Spain, Portugal, France, England, the Italian states, and the Netherlands. This diversity led Thornton to describe the "exploration of the Atlantic" as "a truly international exercise, even if many of the dramatic discoveries were made under the sponsorship of the Iberian monarchs". That gave rise to the myth that "the Iberians were the sole leaders of the exploration".

Slavery had existed in Portugal and Spain throughout recorded history. The Roman Empire had established its system of slavery in ancient times. Benjamin Isaac posits a proto-racism that existed among Greco-Roman people, referring to Aristotle's statement in his Politics that "slaves are subhuman or lesser men while masters are superior", to justify the inferior status of slaves. Since the fall of the Western Roman Empire, systems of slavery continued in the successor Islamic and Christian kingdoms of the Iberian Peninsula through the early modern era of the Atlantic slave trade. Arlindo Caldeira writes that in 1444, six caravels belonging to a consortium of seamen and merchants docked in Lagos with a cargo of 235 enslaved men, women, and children who had been captured in the Bay of Arguin in what is today Mauritania. These were mostly Muslim Berbers, but also, for the first time, included black-skinned people, likely from sub-Saharan Africa, who had been brought to North Africa over the Trans-Saharan caravan routes. Caldeira says "historians recognized this episode as the beginning of the Atlantic slave trade", although ships in Prince Henry the Navigator's fleet had been bringing enslaved persons from West Africa since 1441. The Portuguese established their first trading post as early as 1448 at Arguin, and in 1455 built a fortress to defend the Portuguese merchants settled there.

In the Middle Ages, religion and not race was a determining factor for who was considered to be a legitimate target of slavery. While Christians did not enslave Christians and Muslims did not enslave Muslims, both allowed the enslavement of people they regarded as heretics or insufficient in their religion. This allowed Catholic Christians to enslave Orthodox Christians, and Sunni Muslims to enslave Shia Muslims. Christians and Muslims approved of enslaving pagans, who came to be a preferred and comparatively profitable target of the slave trade, though on a much smaller scale than the trade in sub-Saharan Black African slaves. White slavery was notable throughout the 14th and 15th centuries, and white slaves were one of the largest slave populations. The slaves sold in Spain during medieval times came from the Black Sea area and the Balkans via the Balkan slave trade and the Black Sea slave trade.

In the 15th century, the Balkan slave trade was taken over by the Ottoman Empire, and the Black Sea slave trade, supplanted by the Crimean slave trade, was closed off from Europe. Spain and Portugal replaced this source of slaves by importing slaves from the conquered Canary Islands and then from mainland Africa. The mainland trade was initially from Arab slave traders, via the Trans-Saharan slave trade from Libya, and then from the African West coast through Portuguese outposts, which developed into the Atlantic slave trade and expanded after the establishment of plantations in the Americas.

By this time, Europeans were using both race and religion as a justification to purchase enslaved sub-Saharan Africans. An increase of enslaved African people from Senegal occurred in the Iberian Peninsula in the 15th century. As the number of Senegalese slaves grew larger, Europeans developed terminologies that associated slavery with skin color. The largest numbers of enslaved Africans were held in Andalusian towns, especially Seville. Colin A. Palmer says, "In 1479 the Spaniards signed the Treaty of Alcáçovas with the Portuguese, granting traders in that country the right to supply Spaniards with enslaved Africans."

Europeans enslaved Muslims and people practicing other religions as a justification to Christianise them. In 1452, Pope Nicholas V issued the papal bull Dum Diversas which gave the King of Portugal the right to enslave non-Christians in perpetual slavery. Thomas says "[t]his clause was obviously intended to include the natives of West Africa." In 1454, Pope Nicholas issued Romanus Pontifex, which laid the foundation for doctrines supportive of empire building.

According to Thomas, conversos, former Jews who had been forcibly converted to Christianity, financed much of the slave trade in Lisbon during the 16th and 17th centuries. He writes that one can speculate how far Muslim mullah-merchants controlled the medieval trade in Black Africans across the Sahara before Portuguese ships were seen in West Africa. In New Spain, Spaniards applied the concept of limpieza de sangre (blood purity) to Africans and Native Americans. Believing their ancestries to be impure even though they might be "New Christians", the Spaniards created a racial caste system, with Black blood more often considered a blemish on a person's lineage.

Ellen Yvonne Simms cites Morner's proposition of three main types of social stratification in colonial New Spain: a caste system, in which membership was set by birth, the estate system, a hierarchy in which rank was determined by customs and laws, and a class system based mainly on economic disparity which allowed upward social mobility. According to Simms, their racist ideology allowed the Spaniards to build a society in colonial New Spain based on racial distinctions, with a white Spanish elite minority controlling all its social, economic, and political aspects, and dominating a large indigenous population alongside the numerous enslaved Blacks who remained at the bottom of the social hierarchy.

Slavery was prevalent in many parts of Africa for many centuries before the Atlantic slave trade. Claire C Robertson writes that while chattel systems aimed to sustain a permanent underclass available for cheap labor, African slavery "historically did not conform to a typical chattel slavery model but was highly varied, especially for women." Historians of African slavery have now generally absorbed the Miers and Kopytoff concept of slavery as a continuum of statuses rather than as a monolith, and have discarded chattel slavery as the paradigm of all slavery. Slavery remained a significant part of the African economy after slave exports declined and then collapsed in the second half of the 19th century. Consequently, slaves were used more widely in the African economy.

Millions of enslaved Africans were transported to other parts of Africa, or exported to Europe and Asia prior to the Atlantic slave trade and the European colonization of the Americas. The Trans-Saharan slave trade across the Sahara had functioned since antiquity, and continued until the 20th-century. Slaves from eastern Sudan, Somalia, and Ethiopia were marched in shackles to the coast and packed into dhows and trafficked across the Red Sea or the Gulf of Aden to markets in Arabia, the Persian Gulf, and the Indian Ocean.

Yves Beigbeder says 5.15 million slaves were sold in Muslim countries from the 16th to the 19th centuries, and cites Roger Botte's estimate that until the 20th century from 12 to 15 million Africans were sold in the Arab slave trade. Raymond Mauny estimates a total of 14 million Black slaves were traded in Muslim countries through the 20th century, including 300,000 for part of the 20th century.

According to John K. Thornton, Europeans usually bought enslaved people who had been captured in endemic warfare between African states. People living around the Niger River would be transported from these markets to the coast and sold in European trading ports, in exchange for muskets and manufactured goods such as cloth or alcohol. The European demand for slaves provided a new and larger market for the already existing trade. While those held as slaves in their region of Africa could hope to escape, those shipped away had little chance of returning to their homeland.

According to Michael A. Gomez, after Muslim rule in Portugal ended in 1250, labourers became scarce when the Muslim populace fled to Granada and the supply of prisoners of war ceased. The Portuguese then began to replace their labour force with West Africans they purchased from Muslim traders. Portuguese activity in the Atlantic trade can be said to have begun with Prince Henry the Navigator, who initiated exploration further south along the West African coast. In 1441 Nuno Tristão and Antão Gonçalves reached Cape Blanc, where they took prisoner eleven Tuareg (Berber) men and one Black woman. The captives were first taken to Portugal and then were returned to West Africa and exchanged for gold dust, ten Black persons, and ostrich eggs.

Upon discovering new lands, European colonisers began to migrate to and settle in lands outside their native continent. Off the coast of Africa, European migrants, under the directions of the Kingdom of Castile, invaded and colonised the Canary Islands during the 15th century, where they converted much of the land to the production of wine and sugar.

The first enslaved Africans arrived in continental North America in the 16th century, often with European explorers. They continued to arrive in limited numbers, not only from Africa but also from Europe, the Caribbean islands, and other Atlantic coastal regions. During the first Atlantic slave trade system, most of the slavers were Portuguese, giving Portugal a near-monopoly. The Treaty of Tordesillas did not allow Spanish ships in African ports. Spain relied on Portuguese ships and sailors to bring slaves across the Atlantic. From 1525, slaves were transported directly from the Portuguese colony of Sao Tomé across the Atlantic to Hispaniola. According to Matthew Restall, by the late 1530s there were probably a thousand Blacks in greater Peru, and possibly twice that number by the mid-1540s. Despite the fact that the Spanish civil wars of the 1540s may have slowed imports of slaves and the emigration of Black auxiliaries from Panama, there were some 3,000 Blacks in Peru by the 1550s.

In 1562, John Hawkins initiated the English slave trade when he sailed as far south on the Guinea coast as Sierra Leone, and according to Hakluyt captured 300 Africans that he transported across the Atlantic to Hispaniola. In 1564, he repeated the voyage, this time using one of the largest ships in Queen Elizabeth's navy, the dry rot-riddled Jesus of Lübeck, and realised a good profit. He sailed on a third voyage in 1567, which, although it ended in disaster with only 15 or so survivors among a crew of 408, was a financial success, with nearly all its treasure of gold, silver, and pearls arriving safely in Plymouth.

Around 1560, the Portuguese began a slave trade to Brazil. From 1580 until 1640, Portugal was temporarily united with Spain in the Iberian Union. Most Portuguese contractors who obtained the asiento between 1580 and 1640 were conversos. For Portuguese merchants, many of whom were "New Christians" or their descendants, the union of crowns presented commercial opportunities in the slave trade to Spanish America. Portuguese New Christians increasingly allied themselves with the Jewish merchants who dominated the slave trade in Dutch Brazil.

Until the middle of the 17th century, Mexico was the largest market for slaves in Spanish America. While the Portuguese were directly involved in trading enslaved people to Brazil, the Spanish Empire relied on the Asiento de Negros system, awarding Genoese merchant bankers the license to trade slaves from Africa to their colonies in Spanish America. Cartagena, Veracruz, Buenos Aires, and Hispaniola received most slave arrivals, mainly from Angola. This division of the slave trade between Spain and Portugal upset the British and Dutch who invested in the British West Indies and Dutch Brazil producing sugar. After the Iberian Union fell apart, Spain prohibited Portugal from directly engaging in the slave trade as a carrier. Despite the ban, however, the Portuguese continued to indirectly supply the Spanish American slave trade.

From 1641 to 1789, Spanish transatlantic traffic was operating at trivial levels. In many years, not a single Spanish slave voyage set sail from Africa. The slave trade was opened to the traditional enemies of Spain, causing Spain to lose a large share to the Dutch, French, and English. Unlike all their imperial competitors, the Spanish almost never delivered slaves to foreign territories. Over the course of the Spanish transatlantic slave trade, Spanish slave ships disembarked more than one million captive Africans in the Americas, with Spanish ships transporting four times more Africans than did their counterparts in the US.

In 1672, the Royal Africa Company was founded. In 1674, the New West India Company became more deeply involved in the slave trade. From 1677 the Compagnie du Sénégal used Gorée to house the slaves. That same year the Spanish proposed to get slaves directly from the Dutch West India Company's posts off the coast of Africa, but this was against the Dutch West India Company Charter (1621). The Royal African Company usually refused to deliver slaves to Spanish colonies, though they did sell them to all comers from their factories in Kingston, Jamaica and Bridgetown, Barbados. In 1682, Spain allowed governors from Havana, Porto Bello, Panama, and Cartagena, Colombia to procure slaves from Jamaica.

By the 1690s, the English were shipping the most slaves from Guinea. By the 18th century, Portuguese Angola again become one of the principal sources of the slave trade. After the War of the Spanish Succession, as part of the provisions of the Treaty of Utrecht (1713), the Asiento was granted to the South Sea Company. Despite the South Sea Bubble, the British maintained this position during the 18th century, becoming the biggest shipper of slaves across the Atlantic. Most of the slave trade took place during the 18th century, with the Portuguese, British, and French being the main carriers of nine out of ten slaves abducted in Africa. By the mid-18th century, French Saint-Domingue was the predominant island in the Caribbean. It produced the most sugar of any colony in the Americas, and held the largest slave population in the West Indies. Slave trading was regarded as crucial to Europe's maritime economy, as noted by an English slave trader: "What a glorious and advantageous trade this is ... It is the hinge on which all the trade of this globe moves."

Slave trading became a business for privately owned enterprises, reducing international complications. After 1790, captains often compared slave prices in major markets of Kingston, Havana, and Charleston, South Carolina before deciding where to sell. For the last sixteen years of the transatlantic slave trade, Spain was the only transatlantic slave-trading empire. Following the British Slave Trade Act 1807 and U.S. bans on the African slave trade, it declined, but the period thereafter still accounted for a substantial portion of the Atlantic slave trade. Between 1810 and 1860, over 3.5 million slaves were transported, with 850,000 in the 1820s.

The first side of the triangle was the export of goods from Europe to Africa. African kings and merchants took part in the trading of slaves from 1440 to about 1833. For each captive, the African rulers would receive goods from Europe. These included guns, gunpowder, alcohol, indigo-dyed Indian textiles, and other factory-made goods. The second leg of the triangle, the so-called "Middle Passage", exported enslaved Africans across the Atlantic to the Americas and Caribbean Islands. The third part of the triangle was the return of goods to Europe from the Americas. The goods were the products of slave plantations and included cotton, sugar, tobacco, coffee, molasses, and rum. Sir John Hawkins, often considered the pioneer of the English slave trade, was the first to run the triangular trade route.

Some historians, such as Sophie Campbell, argue that there is over-emphasis on the importance of any triangular trade. Gilman Ostrander denied it was a major factor in colonial commerce and called it a myth. Whilst it was common initially, within 50 years, two-leg voyages to Africa from the Americas started to make up a significant proportion of the whole of the transatlantic slave trade. Though that share fluctuated over time, it is likely that ships based in the New World carried a larger total of enslaved people across the Atlantic from Africa, compared to the numbers moved in ships with a home port in Europe. Ships from the three largest slaving ports in South America (Rio de Janeiro, Salvador and Recife) transported many more captives from Africa than the total of those from the four major European slaving ports (London, Liverpool, Bristol and Nantes).

David Eltis emphasises the importance of the two systems of wind and ocean currents in the North and South Atlantic Ocean that determined how the transatlantic slave trade was physically carried out. One system lies north of the equator and turns clockwise, while the other lies south of the equator and turns counterclockwise. The northern "wheel" connected Western Europe and West Africa with the Caribbean and North America and was dominated by the English, while the southern "wheel" linked West-Central Africa (mainly Angola) directly to Brazil, an enormous traffic controlled by the Portuguese, who for three hundred years carried on the slave trade with the largest volume. Pieter Emmer says there were two Atlantic systems operative in the first phase of the outward expansion of European commercial activity, including the slave trade, during the early modern period. The first one was created by the Portuguese and the Spanish and the second one by the British, the French, and the Dutch.

The Atlantic slave trade was the result, in part, of a labour shortage created by the desire of colonists to exploit New World land and resources for profit. Native peoples were exploited as slave labour by Europeans until a large number died from overwork, Old World diseases, and maltreatment, conditions which also led to low fertility among them. In the mid-16th century, the Spanish New Laws prohibited enslavement of the Indigenous people, causing a labour shortage. Alternative sources of labour, such as indentured servitude, failed to provide a sufficient workforce. Many crops could not be sold for profit, or even grown, in Europe. Exporting crops and goods from the New World to Europe often proved to be more profitable than producing them in Europe. A vast amount of labour was needed to create and sustain plantations that required intensive labour to grow, harvest, and process prized tropical crops. When the enslavement of Indigenous peoples failed to meet their labour demands, the Portuguese and Spanish shifted to the importation of African slaves, followed later by the English and the French. This transition began around the mid-16th century in Iberia, and included Brazil as well; it occurred approximately between 1650 and 1750 in the Dutch, British, and French colonies. West Africa (part of which became known as "the Slave Coast"), Angola and nearby Kingdoms and later Central Africa, became the primary source of enslaved people to meet the increased demand.

Thomas Jefferson attributed the use of slave labour in part to the climate, and the consequent idle leisure afforded by slave labour: "For in a warm climate, no man will labour for himself who can make another labour for him. This is so true, that of the proprietors of slaves a very small proportion indeed are ever seen to labour." The economist Elena Esposito argues that the enslavement of Africans in America was attributable to the fact that the American south was sufficiently warm and humid for malaria to thrive; the disease had debilitating effects on the European settlers. Conversely, many enslaved Africans were taken from regions of Africa which hosted potent strains of the disease, so they had developed resistance. This resulted in higher malaria survival rates in the American south among enslaved Africans than European labourers, making them a more profitable source of labour and encouraging their use.

David Eltis argues that Africans were enslaved by Europeans because of cultural beliefs that prohibited the enslavement of group insiders, even if there was another source of labour available to be enslaved, such as convicts, prisoners of war or vagrants. He argues that traditional beliefs existed in Europe against enslaving Christians, while those subject to enslavement were non-Christians or natives of Africa and their immediate descendants (a slave converting to Christianity did not guarantee emancipation). Eltis also says that while all slave societies have demarked insiders and outsiders, Europeans took this process further by extending the status of insider to the entire European continent, rendering it unthinkable to enslave a European since this would require enslaving an insider.

The trade led to the destruction of individuals and cultures. The historian Ana Lucia Araujo says:The process of enslavement did not end with arrival on the American shores; in this context, the different paths taken by the individuals and groups who were victims of the Atlantic slave trade were influenced by a myriad of factors including the disembarking region, the kind of work performed, gender, age, religion, and language. These elements very often oriented the paths toward freedom available to these men and women.

Patrick Manning estimates that about 12 million slaves entered the Atlantic trade between the 16th and 19th centuries, but about 1.5 million died on board ship. About 10.5 million slaves arrived in the Americas. Besides the slaves who died on the Middle Passage, more Africans likely died during the slave raids and wars in Africa and forced marches to ports. Manning estimates that 4 million died inside Africa after capture, and many more died young. His estimate includes the 12 million who were originally destined for the Atlantic, as well as the 6 million destined for Arabian slave markets and the 8 million destined for African markets. According to Angus Madden, in the 17th century the Dutch, French, and British introduced plantation agriculture to the Caribbean islands seized from Spain. After their indigenous populations had been mostly wiped out, 3.8 million slaves were transported to the Caribbean islands during the colonial period. Between 1500 and 1870, the same number were carried to Brazil.

Most of the Atlantic slave trade was carried out by seven nations and most of the slaves were carried to their own colonies in the new world. But there was also significant other trading which is shown in the table below. The records are not complete, and some data is uncertain. The last rows show that there were also smaller numbers of slaves carried to Europe and to other parts of Africa, and at least 1.8 million did not survive the journey and were buried at sea with little ceremony.

J.C. Sharman writes that enormous growth in the demand for slaves gave African rulers more opportunities for state building. Many of them developed "highly militarized predatory slaving states" that first appeared in West Africa as a consequence of the expansion of the transatlantic slave trade in the late 17th century. These rulers used the increased returns from predatory aggression to build armies and states by conscripting slaves as soldiers and trading for guns. The demand for enslaved persons remained high even after the Atlantic slave trade was abolished, with the number of enslaved Africans reaching its highest point near the end of the 19th century. The presence of European slavers affected the way in which the legal code in African societies responded to offenders. Crimes traditionally punishable by some other form of punishment became punishable by enslavement and sale to slave traders.

According to Patrick Manning, warfare was the principal means by which slaves were captured. He cites as an example the constant wars in the Bight of Benin during the late 17th and early 18th centuries, occurring when slave exports from that region were greatest. He refers to John Thornton's work in recovering descriptions of wars between armies of several thousand in 17th-century Angola, with baggage trains made up mostly of women within each army—slave traders would wait nearby to purchase the defeated combatants, a "preselected population" ready to be exported, from the winners. Thornton identifies two aspects of African societies that inclined them to engage in the slave trade: use of slaves in the domestic economy, especially to raise revenue for consolidating a state, and in warfare. He cites Philip Curtin's analysis of the Senegambian slave trade of the 18th century, from which Curtin derived his view that African warfare leading to slave captures was due to either economic or political factors, although wars might be fought for mixed reasons. He infers that the data support the political model.

Michael A. Gomez says that deaths of captives from initial capture to the barracoons on the coast averaged 10 to 15 per cent, reaching as high as 40 per cent in Angola, while Nathan Nunn says that death rates on the forced marches from inland areas to slave ports on the various coasts are estimated to have ranged from 10 per cent to 50 per cent.

Before the arrival of the Portuguese, slavery had already existed in the Kingdom of Kongo. Afonso I of Kongo believed that the slave trade should be subject to Kongo law. When he suspected the Portuguese of receiving illegally enslaved persons to sell, he wrote to King João III in 1526 imploring him to put a stop to the practice.

Dahomey developed as a warrior-state with an economy that became dependent on the transatlantic slave trade. Its kings sold war captives into transatlantic slavery as their main source of revenue, a trade which was entwined with the religious practise of human sacrifice at the Annual Customs, the kingdom's primary public ceremony. King Gezo was quoted in The Anglo-American Magazine as saying in 1849:The slave-trade has been the ruling principle of my people. It is the source of their glory and wealth. Their songs celebrate their victories, and the mother lulls the child to sleep with notes of triumph over an enemy reduced to slavery. Can I by signing such a treaty, change the sentiments of a whole people? It cannot be! The Empire of Benin grew increasingly rich during the 16th and 17th centuries on the slave trade with Europe; slaves from enemy states of the interior were sold and carried to the Americas in Dutch and Portuguese ships. The Bight of Benin's shore soon came to be known as the "Slave Coast". Like the Bambara Empire to the east, the Khasso kingdoms depended heavily on the slave trade for their economy. A family's status was indicated by the number of slaves it owned, leading to wars for the sole purpose of taking more captives. This trade led the Khasso into increasing contact with the European settlements of Africa's west coast, particularly the French.

In 1807, the Parliament of the United Kingdom passed the bill that abolished the trading of slaves. According to the historian Kenneth Onwuka Dike, the European abolition movement was puzzling to contemporary Africans, as the English, who had been preeminent in the slave trade, suddenly began opposing it zealously. The trade had been the foundation of the economies of the slave-trading African kingdoms including Dahomey, Bonny, Lagos, and many others that owed their existence and power to the rise of the slave trade. The king of Bonny (now in Nigeria), the predominant slave market in Africa, declared in 1807 (paraphrased):We [i.e. the king and Council] think that this trade must go on. That also is the verdict of our Oracle and the priests. They say that your country, however great, can never stop a trade ordained by God himself.

After being captured and held in the factories, enslaved persons were shipped on the infamous Middle Passage across the Atlantic Ocean, on which staggering numbers of them died. Their deaths were the result of brutal treatment and poor care from the time of their capture and throughout their voyage, on which they were packed into tight, unsanitary spaces aboard ships for months at a time. Measures were taken to stem the onboard mortality rate, such as enforced "dancing" (as exercise) above deck and the practice of force-feeding enslaved persons who tried to starve themselves. The conditions on board also resulted in the spread of fatal diseases. Other fatalities were suicides, slaves who escaped by jumping overboard.

Radburn and Eltis describe how the famous diagram of the Liverpool slave ship Brooks published in January 1789 by the Society for Effecting the Abolition of the Slave Trade has come to symbolise the horrors of the captive African experience of the Middle Passage. The society disseminated thousands of copies of the image in posters, newspapers, pamphlets, magazines, and books. The scholars say the French ship Marie-Séraphique better represents typical British and French slave ships in the second half of the 18th century than does Brooks. Marie-Séraphique carried an average of 357 enslaved persons during its six voyages to Africa, while British vessels of the period usually carried about 267 captives and French slavers carried about 325. For comparison, the unusually large Brooks carried more than double the average of British vessels.

Raymond L. Cohn, an economics professor whose research has focused on economic history and international migration, has researched the mortality rates among Africans during the voyages of the Atlantic slave trade. He found that mortality rates decreased over the history of the slave trade, primarily because the length of time necessary for the voyage was declining. "In the eighteenth century many slave voyages took at least 2½ months. In the nineteenth century, 2 months appears to have been the maximum length of the voyage, and many voyages were far shorter. Fewer slaves died in the Middle Passage over time mainly because the passage was shorter."

The ordinary sailors on slave ships were badly paid and subject to harsh discipline. Mortality of around 20%, a number similar and sometimes greater than those of the slaves, was expected in a ship's crew during the course of a voyage; this was due to disease, flogging, overwork, or slave uprisings. Disease (malaria or yellow fever) was the most common cause of death among sailors. A high crew mortality rate on the return voyage was in the captain's interests as it reduced the number of sailors who had to be paid on reaching the home port.

The slave trade was hated by many sailors, and those who joined the crews of slave ships often did so through coercion or because they could find no other employment.

Meltzer states that in the 18th century a third of the Africans who survived the Middle Passage died "while being seasoned for labor", a brutal process. Amoebic dysentery was the leading cause of death. Gomez describes the "seasoning" captives underwent after they were transferred from the slavers to their buyers in North America, a period of acculturation in which they had to adapt to a different land with different food, different clothes, and a different climate. They also had to accept the reality of being a slave in a new part of the world and the realization that the degradation they suffered had more to do with their being Africans than with their status as slaves. Upon their disembarkation, they were issued a set of clothes of a coarse material spun from flax or hemp. Then they began the period of seasoning that could last from one to three years. Mullin, among others, argues that newly arrived Africans in Virginia were not seasoned or broken in, but were immediately put to work in the fields to harvest the year's last crops. Gomez says that along the South Carolinia coast, however, a group of new African arrivals were broken in by reliable slaves called "drivers" who taught them the skills they would need to perform their jobs. This instruction was reinforced with light punishments, including the denial of food. Africans imported into Louisiana were treated differently—they were divided into small groups under the instruction of older slaves. A slower approach was used to avoid pushing slaves "too far too fast" and thereby causing them to run away, die from distress and disease, or commit suicide. Slaveholders looking to maximize the return on their investment had to moderate their treatment of the enslaved.

The historian Carolyn E. Fick cites the estimate of Hilliard d'Auberteuil, a French lawyer who lived and practiced in Saint Domingue for several decades in the 18th century, that between 1680 and 1776, more than 800,000 enslaved people were brought from Africa to Saint Domingue. By the end of that interval, at the time he was writing, there were only 290,000 Africans living in the colony, over one-third of those transported having died within the first few years. The historical researcher Gabriel Debien found that generally half of newly enslaved Africans died during the first three to eight years of their servitude.

Klas Rönnbäck writes that during the period of the early modern Atlantic world, sugar production, mostly for European markets, grew to depend on the forced labor of slaves of African descent. The growing demand for sugar and the natural decrease of the slave population (a result of the routine of hard labor and an inadequate diet) were the main drivers for the expansion of the transatlantic slave trade. Michael Tadman says that among the enslaved population in the antebellum US there was a natural increase of about 25 percent per decade. In stark contrast to this statistic, Brazilian and Caribbean slaves commonly suffered rates of natural decrease of 20 percent per decade. By 1800 and even afterwards, Africans, rather than Creoles (those born in-country), composed a majority of the slave populations of Brazil and of the British and French Caribbean. According to Tadman, sugarcane planters would always demand a predominantly male workforce and would always seek to import slaves when a supply was available because of the high rates of natural decrease in sugar-producing areas. During slavery, it was the free mixed-race and free black populations, along with the Maroons, that experienced relatively high fertility rates, while low levels of fertility were typical of the enslaved populations.

Kenneth F. Kiple argues that the slave populations of the West Indies suffered natural decrease because of the combined effects of genetic, immunological, cultural, and above all, nutritional factors. Common wisdom among West Indian planters and physicians blamed "locked jaw" (neonatal tetanus), caused by improper care of the umbilical cord, as the primary cause of infant death among the enslaved. Infantile beriberi, caused by thiamine deficiency, may have been a decisive factor itself in suppressing the natural growth of the Caribbean slave population. Neonatal tetany, caused by deficiencies of calcium, magnesium, and vitamin D, with symptoms involving muscle seizures, caused many infantile deaths, while kwashiorkor, a severe form of protein malnutrition, caused the deaths of many children after weaning. Deaths are frequently attributed to diarrhea or worms in areas where kwashiorkor is prevalent, and these two causes of death appear to have caused most of the deaths among enslaved children who had survived infancy.

The historian Martha Santos writes that as the transatlantic slave trade was legally suppressed in Brazil in 1831, and fully abolished in 1850, it became more difficult to replenish the supply of slaves, and the inter-provincial trade increased greatly. The planter class, wanting to maximize profits from their existing stock of slaves, considered enslaved women's reproductive capacity and their mothering labor as central to replacing the African captives who had formerly been imported in the trade. Brazil enforced the principle of partus sequitur ventrem, the doctrine that children of enslaved mothers inherit the legal status of their mothers, as legal justification for the perpetuation of slavery. Slavery itself was finally abolished in Brazil in 1888.

Birth rates were low for the first generation of slaves transported from Africa, but, in the US, may have increased in the 19th century to some 55 per thousand, approaching the biological maximum for human populations.

According to Aisha Djelid, planters hired out enslaved men to other plantations so they could impregnate enslaved women; the enslavers regarded these interactions as business transactions. The value of enslaved women decreased as their fertility decreased, so their enslavers encouraged them to reproduce at a very young age. The imperative of reproducing forced on enslaved young girls and women caused them to have reproductive health problems. Enslaved women found ways to resist forced reproduction by causing miscarriages and abortions by using plants and medicines.

Slaveholders tried to control enslaved women's reproduction by encouraging them to have relationships with enslaved men. "Some slaveholders took matters into their own hands, however, and paired enslaved men and women together with the intent that they would procreate." Enslaved girls and women were forced to give birth to as many slaves as possible. The mortality rate of enslaved mothers and children was high because of poor nutrition and sanitation, lack of medical knowledge, and overwork. The historian Anthony Gene Carey refers to a list compiled for Confederate tax purposes by the Cunningham family in Georgia as an example of the typical pattern on plantations: women beginning to bear children in their late teens or early twenties and giving birth every two or three years into their early forties. The demands of the regime of heavy labor on plantations along with poor nutrition and/or disease could also lead to lower birth rates. The economist Michael Haines writes that around 1850, African Americans in the United States, who were mostly slaves at the time, "had an estimated life expectancy at birth of 23 years (40 percent lower than for whites) and an estimated infant mortality rate of about 340 (61 percent higher than for whites)."

According to Antonia Sohns, between 1790 and 1800, nearly 1 million enslaved people in the United States were "sold down the river", meaning they were moved forcibly from the Upper South to the Lower South. They were torn from their families into a brutal life of hard labor and injustice. The Act Prohibiting Importation of Slaves, promoted and signed by Thomas Jefferson and enacted on 1 January 1808, prohibited the importation of slaves into the United States. The decline of the Atlantic slave trade to the United States caused an increase in the domestic slave trade.

Regarding claims there was a sizable clandestine traffic in enslaved Africans between the island of Cuba and Florida after 1808, Kiple says statistical evidence and historical inquiries discourage belief in a large contraband slave trade to the United States during this period, therefore the existence of a substantial Cuba to Florida slave traffic is unlikely. He cites Philip D. Curtin's estimate that the total number of slaves brought to the United States during the years 1808-1861 was not more than 54,000. Fernandina, located in Spanish Florida on Amelia Island, just south of the border with the US, became a free port in 1808. Slave traders then preferred to carry on their business at its deep-water port rather than at St Augustine and the town became a resort for smugglers. The Spanish authorities in La Florida welcomed the increased industry and tax revenues brought by the slave trade, and encouraged slave traders to set up operations there. According to Frances Stafford, a long and mostly uninhabited coastline and its proximity to Cuba made Florida an ideal location, and as early as 1810 it was a centre of slave trading. Florida remained under Spanish control until 1821 when it was ceded to the United States.

By a treaty Spain signed with Britain in 1817, the Atlantic slave trade exportation of slaves to Cuba became illegal in 1820; however, the Cuban authorities were uninterested in abolishing slavery, and slave ships continued to bring enslaved Africans from Africa. The last slave ship known to reach the island made its voyage in 1867, but the institution of slavery itself was not abolished until 1886.

Jorge Felipe, a researcher and contributor to the SlaveVoyages project, analysed intra-American and transatlantic voyages to Cuba between 1790 and 1820. His data shows intra-American and transatlantic slave arrivals to Cuba increased significantly in this period, followed by a higher peak of direct transatlantic arrivals from 1820 to 1860. The historian Jennie K. Williams writes that the coastwise trade in the United States was conducted via the Atlantic Ocean and/or the Gulf of Mexico. The greatest part of this trade involved enslaved people being carried forcibly to New Orleans, the largest slave market in the country at the time. Relying only on extant records, she finds that between 1818 and 1860 more than 63,000 enslaved people were trafficked to New Orleans in coastwise ships.

The costs of the shipment of human cargo from Africa and operating costs of the slave trade from Africa into Cuba rose in the mid-19th century. The historian Laird Bergad writes of the Cuban slave trade and slave prices: "Three interacting factors produced the overwhelming demand for slaves responsible for pushing prices to the high levels [...] The first was the uncertainty surrounding the future of the slave trade itself. The long and persistent British campaign to force an end to the Cuban trade had traditionally been circumvented by collusion between Spanish colonial officials and Cuban slave traders. An additional obstacle to British efforts was the unwillingness of the United States to permit the search of US-flag vessels suspected of involvement in the slave trade". As the cost of sugar increased after 1855, the prices of prime-aged slaves, those 15 to 40 years old, moved upward. According to Bergad's 1987 study, in 1860 about 39.6 percent of slaves sold in Matanzas were young prime aged Africans of either sex; in 1870 the percentage was 74.3 percent.

Texas was part of Mexico from 1821 until 1836, and its coast on the Gulf of Mexico provided an ideal location for pirates and privateers to base their operations. Cuba was a key distribution centre for the African slave trade into Latin America, and because it was relatively close to Galveston Island at a distance of 800 miles, it became the main source of enslaved Africans for Anglo-American settlers in Texas. Galveston was also only about 60 or 70 miles away from the Louisiana border on a very shallow coastline; consequently smugglers utilised its location to their advantage and illegally transported enslaved Africans from Cuba, selling them to slaveholders in Texas and Louisiana. The French pirate and privateer Jean Lafitte established a colony on Galveston Island in 1817 and cruised as a privateer for four years, making a profit by smuggling in African slaves and selling them to slaveholders in the United States. Lafitte used intermediaries such as the Bowie brothers, John, Resin, and James, who contracted with planters from the United States looking to buy slaves. John Bowie bragged that between 1818 and 1820 the brothers had made $65,000 smuggling Africans into the US and selling them to planters in Mississippi and Louisiana.

Sean M. Kelley says the total number of African or other foreign-born captive persons disembarked in the United States after 1820 was very small. As Mexican Texas began to develop its own plantation economy in the 1830s, smugglers bought about one thousand enslaved Africans in Cuba and moved them to the lower Brazos River, where they became "the largest African-born community in the antebellum United States". The historian Ernest Obadele-Starks, referring to calculations made by Curtin, deduces that after 1808 the number of enslaved Africans smuggled into the United States annually averaged as low as 3,500.

The last slave ship known to have landed on US soil was the schooner Clotilda, which in 1860 illegally smuggled 110 Africans into Mobile Bay.

The historian Pierre Force says that according to Ira Berlin's concept of Atlantic Creoles, they originated when Africans first encountered Europeans on the western coast of Africa in the 15th century. Berlin uses the term to refer to those who "became part of a new culture that emerged along the Atlantic littoral—in Africa, Europe, or the Americas—beginning in the 16th century." Many Atlantic creoles of the 17th century found themselves enslaved, and those transported to the North American coast were able to establish themselves in the new environment, where their knowledge and their "ability to negotiate with the diverse populace" were valued. This allowed them to establish their place in the developing social order. Some Atlantic Creoles achieved freedom, married, sometimes intermarrying with whites, and became property owners, interpreters, farmers, and even slaveholders themselves. The historian Ira Berlin gives the example of Anthony Johnson, who was sold to the English in 1621 at Jamestown and who, by his own efforts, gained freedom for himself and his family. He and his sons became independent farmers, held slaves, and left their heirs considerable estates.

Berlin demonstrates how Atlantic Creoles emerged in the 15th century around the transatlantic trading factories established by Europeans along the coast of Africa. Many of them functioned as liaisons in these trading enclaves, where they used their linguistic skills and their knowledge of the Atlantic coast's cultural conventions, commercial practices, and diplomatic protocol to work as middlemen between the African merchants and European shipmasters. Some Atlantic Creoles represented the interests of those parties who belonged to the race they identified with, and acted as their agents in negotiations while others assumed the racial identity of whoever paid best. They were often multilingual and worked as "merchants, slave traders, linguists, sailors, artisans, musicians, and military figures." They traded with Europeans along the African coast and established Creole communities in Africa and the Americas. With the European settlement of lands in the New World, the main destination of the Atlantic slave trade shifted from Europe to the Americas, where slavery weighed heavily on Atlantic Creoles.

To overcome language difficulties between Africans and Europeans, nonverbal communication such as signs and gestures was sometimes resorted to, but their use was limited and they were easily misunderstood. A more effective means of communicating was by using African interpreters, both enslaved and free, to facilitate exploration and trade between the groups. A trade language emerged along the African coast during the Atlantic slave trade period with a mix of West African and European languages called English Creole. Multiple African pidgin English languages developed along the West and Central African coast.

Abdul Karim Bangura describes the pidgin used by slave owners and slave traders as a lingua franca that covers a range of regional hybrids. Bangura refers to Tom McArthur's noting that "some researchers have proposed a family of 'Atlantic creoles' that includes Pidgin in West Africa, Gullah in the United States, and the various patois of the Caribbean." Gullah is the Creole language of the African population of the Sea Islands in South Carolina, Georgia, and Florida. Gerardo Lorenzino writes that "Angolar is the language spoken by descendants of maroon slaves who escaped from Portuguese plantations on São Tomé beginning in the mid-sixteenth century". These slaves contributed to the formation of Angolar Creole Portuguese. Some revolts on slave ships were deterred by European traders who purposely chose Africans who spoke different languages. This contributed to the further evolution of African Pidgin English. Makeshift pidgin languages evolved when enslaved Africans in the New World needed to communicate with the slavers and among themselves, with each side using the grammar of their native language. The enslaved borrowed vocabulary from the language of the slave masters to express content in their speech.

According to the historian Jane Landers, historians who study Atlantic Creoles argue that despite their subordinate status, Atlantic Creoles who lived "on the African coasts, in Europe, or in the Americas" engaged in various economic, political, social, cultural, and religious systems, without an implication that they lost some part of their original cultural foundations. They interacted with a wide range of Indigenous and European groups and "helped shape a new Atlantic world system". The historian Philip Morgan says "blacks were the most linguistically polyglot and proficient ethnic group in the Americas." Salikoko Sangol Mufwene has advanced a thesis regarding the genesis of Creole languages considered in the light of ecological linguistics. He posits that as populations on plantations increased more by the importation of new labour both from Africa and Europe than by births, the rapid increase affected the emerging structures of labourers' vernacular speech. Because the African slaves had little contact outside their working hours with Europeans, even with those indentured servants who laboured with them, newly arrived Africans learned the colonial vernacular of their enslavers mostly from the Creole and 'seasoned' slaves.

Blassingame says slaves influenced the formation of language in the southern United States by forcing whites who tried to communicate with them to learn African words, and by combining "African forms, Biblical lore, and archaic Anglicanisms", introduced new idiomatic expressions to their speech. Glassman describes how Creole language developed simultaneously and independently in Haiti and Louisiana along similar lines. Creole (Kreyòl) allowed the enslaved to communicate in a coded language by which they were able to organize the Haitian Revolution undetected by the French.

According to the economic historian Barbara L. Solow, the value of British sugar imports by 1660 was greater than that of all other colonial products combined, and by I774 sugar accounted for 20 per cent of total value of imports, far exceeding any other commodity. In the first half of the 18th century, the British were responsible for a third of the European consumption of sugar, all of it produced by slave labor. Although Britain had entered the sugar colony business late, from around 1720 its colony of Jamaica emerged as the greatest sugar-producing island in the British West Indies.

Frank Moya Pons writes that with sugar as the foundation of the economy in French St Domingue (western Hispaniola, now Haiti), over the course of the 18th century the production of its plantations exceeded that of all the British West Indian colonies put together. By the end of the century, with substantially lower production costs, the French were able to undersell the British in the European sugar market, and after the end of the War of American Independence in 1783, sugar production in the colony reached their highest levels ever. To meet the increasing labour demand, the planters of St Domingue were importing an average of 30,000 African slaves annually before the French Revolution.

Guillaume Daudin says the plantation system established itself as the main support of long-distance trade in 18th-century France. The French trading economy was the biggest in Europe at the end of the 1780s, the total value of its long-distance trade being equal to 25 million pounds sterling, while the total value of British long-distance trade was only 20 million pounds sterling. He finds in his analysis that considering returns, liquidity, maturity, and risk, investments in the slave trade and other long-distance trade were safer and of shorter lifespan than government bonds. Returns for investors in overseas trade voyages averaged around 6 percent; as compared to 5 percent for most domestic alternatives.

The Slavery Abolition Act of 1833 emancipated over 800,000 enslaved persons when it was passed by the British parliament. As part of the compromise made to secure it, the bill also provided compensation for citizens who declared their loss of 'property', setting off what Nicholas Draper says "could be characterised as a feeding frenzy" among slave-owners, those whose families had once owned slaves, and other financial beneficiaries of slavery. The British Government created the Slave Compensation Commission to administer the distribution of £20 million in compensation for over 45,000 individual claims from the former owners of 800,000 persons who had been enslaved.