The Haymarket incident, Haymarket massacre or Haymarket revolt was a historical event that took place in Haymarket Square (Chicago, United States) on May 4, 1886 and that was the high point of a series of protests that from the 1st of May had occurred in support of the striking workers, to claim the 8-hour workday. During a peaceful demonstration an unknown person threw a bomb at the police trying to dissolve the act violently. This led to a trial, years later described as illegitimate and deliberately malicious, towards eight anarcho-communist and anarcho-communist workers, where five of them were sentenced to death (one of them committed suicide before being executed) and three were detained. They were called Martyrs of Chicago by the workers movement.
On June 21, 1886, the case against 31 officials began, and the number was reduced to eight. Although the trial was at all times a farce and was held without respecting any procedural rule, the yellow press held the guilt of all the accused and the need to hang foreigners. Although nothing could be proved against him, the eight of Chicago were found guilty, accused of being enemies of society and the established order. Three of them were sentenced to prison and five to the gallows.
Therefore we can say that the trial and sentencing had as its primary objective, to finish or disarm the nascent labor movement.