In 1910, Chicago was segregated due to housing. During this period, the Great Migration took place, so a large number of Black people from the South moved to bigger cities in the North and West. Cities like Chicago were particularly impacted. Although Chicago formally banned segregation in the 1870s and 1880s, the city remained a divided place. By 1910, more than seventy-five percent of the 44,000 Black people living in Chicago resided on the South Side. This area was called the Black Belt. With increasing belligerence, white people enforced this de facto segregation.
In 1917, the Chicago Real Estate Board (CREB) convened a Special Committee on Negro Housing to figure out how to keep Black and white residents separate. The CREB would decide which areas in Chicago would sell to Black people and which sections would be open to white people only.
During the 1910s, Chicago was also effectively segregated in terms of education, jobs, and union membership. The lakes, too, were, in practice, segregated. Near the end of July 1919, a Black teen named Eugene Williams went swimming with his friends in Lake Michigan. Apparently, they had crossed an invisible boundary that separated the white side of the lake from the Black side of the lake. Upset over the supposed transgression, a handful of white people started to throw stones at the boys. Eugene drowned to death after being hit in the head with a stone. Eugene's murder set off a series of violent riots.