Haymarket Riot

«In 1886, a broad coalition of labor organizations joined to campaign for an eight-hour workday. On May 1, 1886, this coalition initiated a general strike throughout the United States, the effects of which were particularly strong in Chicago. On May 3, fighting broke out at the McCormick Reaper Works in Chicago, and at least two workers were killed by the police.

Outraged at these killings, anarchists, members of the labor movement, and other radicals met for a rally in Chicago's Haymarket Square on May 4. The rally was peaceable until the police attempted to disperse the crowd. Then a bomb was thrown into the police ranks, killing seven officers and wounding sixty more. The police fired in response, killing and wounding like numbers of participants.»


from here