Haymarket affair

On the night of 4 May 1886, as police moved to break up a labour rally in Chicago's Haymarket Square, someone threw a dynamite bomb into their ranks. The explosion and the gunfire that followed left seven police officers and at least four civilians dead. Eight anarchists were convicted of conspiracy although the bomber was never identified, and four were hanged. The case became a cause for labour movements around the world and lies behind the choice of 1 May as International Workers' Day.

Industry in the United States grew rapidly after the American Civil War. Chicago in the 1880s, rebuilt after the Great Chicago Fire, was a major industrial centre with a large German and Bohemian immigrant workforce, and American workers typically put in over 60 hours across a six-day week. In 1884 the Federation of Organized Trades and Labor Unions resolved that the eight-hour day should become standard from 1 May 1886. On that Saturday somewhere between 300,000 and half a million workers across the United States struck, perhaps 30,000 to 40,000 of them in Chicago, where an anarchist movement of several thousand, mostly immigrant workers, centred on the German-language Arbeiter-Zeitung, edited by August Spies.

On 3 May Spies addressed strikers outside the McCormick Harvesting Machine Company works. When workers surged towards strikebreakers leaving the plant, police opened fire, killing two strikers. Anarchists printed leaflets calling a protest meeting for the next evening. The first version urged workers to arm themselves; Spies refused to speak unless the line was removed, and most copies were destroyed.

The rally on 4 May began calmly, in light rain, before a crowd variously estimated at 600 to 3,000. Spies, Albert Parsons and the Methodist preacher Samuel Fielden spoke, and Mayor Carter Harrison, finding nothing alarming, went home. At about 10.30 p.m., as Fielden was finishing, a column of police arrived and ordered the meeting to disperse. A bomb landed among them, fatally wounding Officer Mathias Degan. Shooting broke out at once. Historians disagree over who fired first and how many police were hit by their own colleagues' bullets in the dark and confusion.

A wave of raids, arrests and press hysteria followed, aimed especially at anarchists and immigrants. Eight men were indicted as accessories to murder, though only two of them were at the square when the bomb exploded. The trial, before Judge Joseph Gary, ran from June to August 1886. The prosecution argued that the defendants' speeches and writings had encouraged the unknown bomber, making them equally guilty. All eight were convicted: seven were sentenced to death and Oscar Neebe to 15 years. Fielden and Michael Schwab had their sentences commuted to life imprisonment; Louis Lingg killed himself in his cell; and on 11 November 1887 Spies, Parsons, Adolph Fischer and George Engel were hanged.

In 1893 Governor John Peter Altgeld pardoned the three surviving prisoners, condemning the trial for its packed jury and biased judge and noting that no link to the bomber had been shown. Most historians have since regarded the case as a serious miscarriage of justice. The historian Timothy Messer-Kruse has challenged this view. Historians including James Joll and Messer-Kruse point to Rudolf Schnaubelt, a police suspect, who fled the country, as the likely bomber.

Employers took the opportunity to crush unions, and longer working days returned. Yet the campaign for eight hours revived, and in 1889 the Second International, meeting in Paris, called for worldwide demonstrations on 1 May 1890, partly in memory of the Haymarket dead. May Day has been marked by workers in many countries ever since. The defendants' grave in Forest Park, Illinois, was made a National Historic Landmark in 1997.

Our 1880 and 1900 maps show the United States in the decades of rapid industrial growth during which the affair took place.