On May 3, 1886, unarmed strikers clashed with police at Chicago’s McCormick Reaper Works factory. The deaths of six workers became a call for direct action, and a public rally was called for the following day to be held in Haymarket Square. Again, the police and the strikers clashed, but this time, a bomb was thrown, resulting in the death of seven police officers and multiple other injuries. The police, uncertain about the source of the bomb, fired into the crowd, killing four of the demonstrators....