May 4, 1886: A bomb kills 12 people (including eight police officers) during a labor rally on Chicago’s near West Side. The bomber was never caught, but police arrested eight leaders of the rally, who were subsequently convicted despite the lack of evidence tying them to the attack. A year and a half after the bombing, despite a worldwide outcry at the miscarriage of justice, four of the organizers were hanged, and one committed suicide.
Actually, I wasn’t thinking of the anniversary at all, but I saw it in a list of events for May 4 (for me, May 4 is mostly the day in 1864 U.S. Grant launched his bloody but ultimately successful campaign against Robert E. Lee’s Army of Northern Virginia). Taking a very short look around, I found a couple of great online resources about Haymarket (which resonated through Illinois and national politics for years afterward and played a role in one of my favorite historical novels, Howard Fast’s "The American," about the life of Governor John P. Altgeld). Check out the Chicago Historical Society’s detailed history of the case. Also good: The Chicago Public Library’s online Haymarket collections (from which the picture above is taken), which includes a brief writeup on the history of the famous (in Chicago) Haymarket statue memorializing the police victims of the bombing and was still attracting bombing attempts as late as 1970.