There were far fewer explicitly racist laws in the northern states, but these regions were still able to achieve a very strict racial segregation within their population that was as rigidly enforced as in the Jim Crow regime. Instead of directly regulating the movement of citizens like the south, various zoning and state and federal housing policies worked to keep Black Americans out of white neighborhoods.
One such strategy was known as redlining. During the Great Depression in the 1930s, the Federal Housing Association (FHA) was created to stimulate the demand for homeownership by insuring mortgages lent out by banks. The FHA and the banks had maps where they drew lines around the Black neighborhoods that they would not insure loans in. This is where the term "redlining" comes from. The FHA claimed that they would only insure mortgages that met particular conditions; but the reality was that they were based on the racial makeup of the neighborhood. So, a loan to buy a house in a majority-white neighborhood would be insured by the FHA without difficulty, whereas the sale of a house in a majority-Black neighborhood would often be denied insurance. This racist condition allowed the FHA to deny Black Americans the right to a home in certain neighborhoods.
This complicated scheme, though technically “colorblind,” resulted in neighborhoods across Chicago (and the nation) that were systemically racially segregated. This, in turn, had broader consequences for how municipal services were administered in the city of Chicago; critical infrastructure such as transportation and public services such as hospitals were more fully funded and supported in white areas, and neglected in Black ones. One of the most striking examples of this was the disparity between Black and white public schools.