Eight people were initially charged in connection with the Haymarket affair. The charges followed the bombing of a labor rally at Chicago’s Haymarket Square on May 4, 1886.
The meeting had begun as a largely peaceful demonstration supporting an eight-hour workday. When police moved to disperse the crowd, someone threw a bomb, and gunfire followed. Seven police officers and at least four civilians died, with many more people injured. The identity of the bomb thrower was never conclusively established.
The eight defendants were prosecuted for conspiracy and connected offenses, even though only two of them were present when the bomb exploded. The trial became one of the most controversial episodes in American labor history. Seven defendants received death sentences, while Oscar Neebe was sentenced to 15 years in prison.
Illinois Governor John Peter Altgeld later pardoned the three surviving imprisoned defendants in 1893, arguing that the trial had been unfair. The affair helped make May 1 an international workers’ day, while the legal case remains a landmark example of contested political justice.