For five days it raged, mostly on the South Side. White mobs attacked isolated blacks. Blacks attacked isolated whites. John Mills, a black Stockyards worker, was riding home when a mob stopped his streetcar and beat him to death. Casmero Lazeroni, a white peddler, was pulled from his horse-drawn wagon and stabbed to death. Thirty-eight people died--23 blacks and 15 whites. By the time the National Guard and a rainstorm brought the riots to an end, more than 500 people had been injured, wounded blacks outnumbering whites by a ratio of about 2-1.Several factors had heightened tension between the races. Drawn by the promise of employment and dignity, Chicago's black population more than doubled from 1916 to 1918. Blacks had balked at joining white-controlled unions, and in the face of violence, black leaders had begun preaching self-defense instead of self-control. But, most important of all, housing in the city's narrow "Black Belt," which stretched south of the Loop, had not kept pace. When blacks began moving into white neighborhoods, whites responded violently, bombing 26 homes in the two years preceding the riot.
One of the riot's great mysteries is whether the city's future boss of bosses, Richard J. Daley, participated in the violence. At the time, Daley belonged to the Hamburgs, a Bridgeport neighborhood club whose members figured prominently in the fighting. In later years, Daley repeatedly was asked what he did during the riots. He always refused to answer.