Home Owners' Loan Corporation Creates Color-Coded Redlining Maps for 200+ Cities

The Home Owners' Loan Corporation (HOLC) produced 'residential security maps' for over 200 American cities between 1935 and 1940. These maps used four color grades — green (best), blue (still desirable), yellow (declining), and red (hazardous) — to rate neighborhoods for mortgage risk. Black neighborhoods in every city were consistently rated 'D' (red) regardless of the physical condition of housing. These maps were shared with private lenders and the FHA, institutionalizing racial exclusion from mortgage credit across the entire country and preventing a generation of Black wealth accumulation.