This 1886 engraving was the most widely reproduced image of the Haymarket affair. It inaccurately shows Fielden speaking, the bomb exploding, and the rioting beginning simultaneously.
The rally began peacefully under a light rain on the evening of 4 May, 1886.
August Spies spoke to the large crowd while standing in an open wagon on Des Plaines Street with a large number of on-duty police officers watching from nearby. According to witnesses, Spies began by saying the rally was not meant to incite violence.
Historian Paul Avrich records Spies as saying “there seems to prevail the opinion in some quarters that this meeting has been called for the purpose of inaugurating a riot, hence these warlike preparations on the part of so-called ‘law and order.’
However, let me tell you at the beginning that this meeting has not been called for any such purpose. The object of this meeting is to explain the general situation of the eight-hour movement and to throw light upon various incidents in connection with it.”
The crowd was so calm that Mayor Carter Harrison, Sr., who had stopped by to watch, walked home early.
Samuel Fielden, the last speaker, was finishing his speech at about 10:30 A.M. when police ordered the rally to disperse and began marching in formation towards the speakers’ wagon.
A pipe bomb was thrown at the police line and exploded, killing policeman Mathias J. Degan. The police immediately opened fire. Some workers were armed, but accounts vary widely as to how many shot back.
The incident lasted less than five minutes. Several police officers, aside from Degan, appear to have been injured by the bomb, but most of the police casualties were caused by bullets, largely from friendly fire.
In his report on the incident, John Bonfield wrote he “gave the order to cease firing, fearing that some of our men, in the darkness might fire into each other.”
An anonymous police official told the Chicago Tribune “a very large number of the police were wounded by each other’s revolvers. …. It was every man for himself, and while some got two or three squares away, the rest emptied their revolvers, mainly into each other.”
About 60 officers were wounded in the incident along with an unknown number of civilians. In all, seven policemen and at least four workers were killed.
It is unclear how many civilians were wounded since many were afraid to seek medical attention, fearing arrest.
Police captain Michael Schaack wrote the number of wounded workers was “largely in excess of that on the side of the police.”
The Chicago Herald described a scene of “wild carnage” and estimated at least 50 dead or wounded civilians lay in the streets.