Redlining was the systemic withholding of home loans and insurance from certain neighborhoods. Economists such as Richard T. Ely theorized about race and property values in the 1920s, and the 1934 National Housing Act created the Federal Housing Administration, whose chief land economist Homer Hoyt wrote the first underwriting criteria. From 1935 the Home Owners’ Loan Corporation drew residential security maps for over 200 cities, grading areas green, blue, yellow or red, the last labeled hazardous. About 85 percent of residents of red areas were white, yet those areas held nearly all urban African American households, and only six majority Black neighborhoods escaped the label. FHA manuals warned against inharmonious racial groups, and from 1945 to 1959 Black Americans received under 2 percent of federally insured loans.

Chicago sociologist John McKnight coined the term in the 1960s. Gale Cincotta and Shel Trapp built National People’s Action, and in Massachusetts the Dukakis administration forced banks to disclose lending by zip code. The Fair Housing Act of 1968, the Equal Credit Opportunity Act of 1974, the Home Mortgage Disclosure Act of 1975 and the Community Reinvestment Act of 1977 followed. Lenders then shifted to reverse redlining, pushing subprime and adjustable rate loans into the same areas before 2008, with high-income Black Americans almost twice as likely to get subprime loans as low-income white Americans. Settlements include Bank of America for $335 million in 2011 and Wells Fargo for $184.3 million in 2012.

• Blockbusting agents stoked white homeowners’ fears, bought cheaply and resold at a premium to minority families shut out of mortgages.
• Some lenders worked with pastors who preached on wealth building to steer congregations toward toxic loans.
• Formerly redlined areas show higher nitrogen dioxide and PM2.5, including near Philadelphia’s Grays Ferry refinery.
• Life expectancy averages 3.6 years lower in redlined areas, and the gap reaches 21 years in one Richmond, Virginia neighborhood.
• A 2019 HUD lawsuit accused Facebook of letting housing advertisers exclude users through proxy categories.