Local governance rules enabled the eventual division of St. Louis City from St. Louis County.

The 1876 Missouri Constitutional Convention formalized rules concerning local governance, including creating an option for cities meeting a minimum population threshold of “adopting a charter of self-government” that would effectively remove them from the oversight of county governance and place them on an equal self-governing standard (Gordan, 2019, p. 22). This development was in fact informed by St. Louis City’s crafting and request, and shortly thereafter the city split from the county in order to exercise this “home rule.” While the concept of “home rule” originally allowed St. Louis City to separate from the county, by 1945 it had been extended to cities with a minimum of five thousand residents–and counties meeting a certain minimum assessed property value. 

This split eventually became a tool to keep Black individuals away from specific areas.

While the decision for St. Louis City to split off from the county may have initially made sense for the city’s interests, as the metropolitan area expanded and pressed against the western county borders and the eastern border with Illinois the urban and suburban growth occurred outside the regulatory oversight of the city (p. 23).

Colin Gordan explained why this created a particular problem for St. Louis:

Because the city could not expand, new residential developments to the west fell under other jurisdictions or created their own. The central planning goal of these private developments and new municipalities, in turn, was to insulate themselves from local costs or threats or burdens–especially industrial land use, multifamily housing, and African American occupancy. The damage here was done not by the divorce of 1876 but by the offspring of that divorce: the extension of home rule to a hundred odd municipal fragments that were–in purpose and practice–predatory, insular, and deeply discriminatory. (Gordon, 2019, p. 23).