The significance of what happened in St. Louis in 1945 can be understood in the context of African American housing patterns in the early twentieth century. In the 1890s, there were no formal barriers preventing African Americans from living anywhere in the city, and neighborhoods were more mixed. However, as developers built larger subdivisions, they began to use racial and religious restrictions as marketing tools to segregate communities.

During the early 1900s, the African American population in St. Louis grew rapidly due to industrial job opportunities and migration from the Jim Crow South. This led to overcrowding and deteriorating conditions in African American neighborhoods. Those who could afford it sought better housing in predominantly white areas, often facing violence and discrimination.

In 1911, the St. Louis Real Estate Exchange and neighborhood improvement associations formed the United Welfare Association, proposing a city ordinance that restricted neighborhood occupancy based on race. This effectively closed off newer housing to African Americans, forcing them into older, poorer sections of the city. Although the ordinance was initially rejected, it eventually passed through a referendum, fueled by propaganda claiming that African Americans as homeowners devalued properties.

By 1916, African Americans seeking better housing had moved into the western blocks of streets like Cook and West Belle Place, which were previously white-dominated. These developments set the stage for the discriminatory housing practices and segregation that would persist in St. Louis, leading to the events of 1945.