Dozens of blacks were killed during а 1917 riot in East St. Louis, Illinois, where employers had recruited black workers in an attempt to weaken unions (most of which excluded blacks from membership). In 1919, more than 250 persons died in riots in the urban North. Most notable was the violence in Chicago, touched off by the drowning by white bathers of a black teenager who accidentally crossed the unofficial dividing line between black and white beaches on Lake Michigan. The riot that followed raged for five days and involved pitched battles between the races throughout the city. By the time the National Guard restored order, 38 persons had been killed and more than 500 injured.
Violence was not confined to the North. In the year after the war ended, seventy-six persons were lynched in the South, including several returning black veterans wearing their uniforms. In Phillips County, Arkansas, attacks on striking black sharecroppers by armed white vigilantes left as many as 200 persons dead and required the intervention of the army to restore order. The worst race riot in American history occurred in Tulsa, Oklahoma, in 1921, when more than 300 blacks were killed and over 10,000 left homeless after a white mob, including police and National Guardsmen, burned an all-black section of the city to the ground. The violence erupted after a group of black veterans tried to prevent the lynching of a youth who had accidently tripped and fallen on a white female elevator operator, causing rumors of rape to sweep the city.