According to this source there was no any particular reason for this accident. Although there was a direct link of the criminal activity in that rally which was supported by labor leaders and anarchists. A strong argument was made as the main reason was against the capitalist system, widespread fear of unionism and other radicalism. It also explains about the clear intention of making bomb and the proper plan to kill people in this rally. So, seven of the eight defendants received death sentences on Nov 11,1887 and one kill himself. The third source I took is under the title of “The Haymarket Affair and the origins of May Day” by Jerry Elmer on 01 May 2012 and it was copyright on Wednesday November 02,2016. He is also an environmental lawyer
