Redlining
I spotted this map in Franklin Delano Roosevelt Museum, which had a special exhibition on FDR and Black African Americans. Redlining Map of Poughkeepsie, New York and its Suburbs, March 1938This redlining map of Poughkeepsie was among the hundreds of "Residential Security Maps" of urban areas created by the Home Owners' Loan Corporation. The maps indicated mortgage lending risk by neighborhood type, including residential, commercial, and industrial areas.