The Haymarket affair (also the Haymarket massacre or Haymarket riot) refers to the aftermath of a bombing that took place at a labor demonstration on Tuesday May 4, 1886, at Haymarket Square in Chicago. It began as a peaceful rally in support of workers striking for an eight-hour day. An unknown person threw a dynamite bomb at police as they acted to disperse the public meeting. The bomb blast and ensuing gunfire resulted in the deaths of seven police officers and at least four civilians.
Haymarket affair: Of the eight defendants, five – Spies, Fischer, Engel, Lingg and Schwab – were German-born immigrants; a sixth, Neebe, was a U.S.-born citizen of German descent. Only the remaining two, Parsons and Fielden, born in the U.S. and England, respectively, were of British heritage.