"Attention Workingmen! Mass Meeting Tonight, at 7:30." This pamphlet was distributed on May 4, 1886. Chicago had been simmering with labor disputes which culminated in a riot at Haymarket Square where eight officers were killed. Use this following site to read the background on the labor movement in Chicago, view primary sources such as pamphlets and newspapers, read the trial transcripts, decipher political cartoons, and use the bibliography for further research.