May 4th, 1886, Haymarket Square, Chicago.
There was rally in support of striking workers. When the police went to break up the gathering, an unknown person threw a bomb at the police. The bombs and ensuing police gunfire resulted in 8 dead pigs, and an unknown number of dead and injured civilians. About 60 police were also injured. Much of the police injury was from friendly fire.
Originally, 7 men, with the exception of Neebe were sentenced to death. After lengthy appeals process, 2 men had their sentences commuted to life in prison.
Louis Lingg committed suicide in prison. On November 11, 1887 Spies, Parsons, Fischer and Engel were hung for murder.
The prosecution admitted that none of the men were actually guilty of that bombing. Many people were of the opinion that the media frenzy around the case and the politics of the men were the reason for their murder by the state.