Although there have been May Day celebrations dating back to ancient times, the current May Day observances often commemorate the Haymarket Martyrs, especially amongst Anarchists. The original Haymarket "Affair," which took place May 1st, 1886 in Chicago, was organized as a strike against inferior working conditions and in support the establishment of an 8-hour workday.
attempt by police to break up the demonstrations led to a riot, which
resulted in several deaths and many injuries. As a result, eight
Anarchist labor organizers were arrested and put on trial for murder.
Although they were arrested more for their political affiliations and
pro-worker activism and little evidence existed tying them to any
deaths, they were all convicted after a heavily biased trial. Of the
eight, four (Albert Parsons, August Spies, George Engel, and Adolph Fischer) were later executed by hanging and a fifth (Louis
Lingg) committed suicide while awaiting execution. The final three (Samuel Fielden,
Oscar Neebe, and Michael Schwab) were eventually pardoned by the governor of Illinois.