Monday, May 3, 1886, proved a dark day in Chicago. First, Chicago’s Knights received word that Powderly had capitulated to Gould in the Southwest strike, and Chicago’s railroads and other large employers hardened their stance against strikers. The strike at McCormick’s Reaper Works had already turned into a guerrilla war between workers and the police, under Bonfield and the Pinkertons guarding what the strikers called Fort McCormick. The police attacked picket lines, and strikers harassed and sometimes attacked strikebreakers as they entered and left the plant.

