Dust Bowl

Through the 1930s, drought and wind stripped the topsoil from vast stretches of the North American prairies, raising storms of dust that darkened the sky as far as the Atlantic coast. The disaster, centred on the panhandles of Texas and Oklahoma, ruined farms, uprooted hundreds of thousands of people and deepened the hardship of the Great Depression. It became known as the Dust Bowl, and it changed how the United States government thought about land and soil.

The southern High Plains are semi-arid, with less than about 500 millimetres of rain a year, and they swing between long droughts and wet spells. Early explorers had called the region the Great American Desert. From the 1860s, however, the Homestead Act and the railways drew settlers onto the plains, and later laws offered larger plots on drier land. Runs of wet years encouraged the belief that farming itself would bring rain.

High wheat prices during and after the First World War pushed farmers to plough up ever more grassland. In parts of the Llano Estacado the farmed area doubled between 1900 and 1920 and then tripled between 1925 and 1930. Tractors and combine harvesters made it possible to cultivate large holdings cheaply. Deep ploughing destroyed the native grasses whose roots had held the soil and kept in moisture, and fields were often left bare through the windy winters.

A long dry period began in the summer of 1930, and drought struck in waves in 1934, 1936 and 1939–1940. With the grass gone, the dried-out soil turned to powder and the wind lifted it in black clouds that rolled across the ground. In May 1934 a two-day storm carried dust as far as Chicago and then to cities on the East Coast, including New York and Washington.

The worst day came on 14 April 1935, "Black Sunday", when a cold front from the north drove a huge wall of dust south across the plains. An Associated Press report on that storm, rewritten by the news editor Edward Stanley, gave the region its name. At its height the erosion affected some 400,000 square kilometres, and by 1936 losses were put at 25 million dollars a day.

Many families who could not grow crops or pay their mortgages lost or abandoned their farms. Roughly 3.5 million people moved out of the Plains states between 1930 and 1940, many of them to California, where they were often called "Okies" whatever state they came from. Most migrants, however, moved shorter distances to less damaged counties nearby. Surveys of those who reached California showed that fewer than half had been doing farm work before they left. John Steinbeck's novel The Grapes of Wrath, Woody Guthrie's songs and Dorothea Lange's photographs, above all Migrant Mother, made their story widely known.

The crisis led to a great expansion of federal involvement in farming and conservation under Franklin D. Roosevelt. The Soil Erosion Service, founded in 1933 under Hugh Hammond Bennett, became the Soil Conservation Service in 1935. A Drought Relief Service bought starving cattle from farmers, and the Civilian Conservation Corps planted more than 200 million trees in a great shelterbelt to break the wind. From 1937 the government paid farmers to adopt contour ploughing, strip farming, crop rotation and terracing. By 1938 the amount of blowing soil had fallen by about two-thirds, and in the autumn of 1939 regular rain finally returned.

Recovery was slow. By 1940 farmland in the most eroded counties had lost far more value than in lightly affected ones, and in badly damaged areas much of that loss was never made good. The worst-hit counties lost population relative to others through the 1950s. Scientists have since linked the drought to unusual sea-surface temperatures in the Pacific and Atlantic oceans.

Our 1930 and 1938 maps show the United States during the Dust Bowl years, with the southern plains of Texas, Oklahoma, Kansas, Colorado and New Mexico at its centre.