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Mapping Racism in the US

The term redlining has become synonymous with discriminatory housing policies and a legacy of racist practices. The situation stems from the 1930s when the federal Home Owners Loan Corporation (HOLC) published city maps categorizing neighborhoods by their alleged mortgage-lending risk. Higher risks were heavily associated with areas where Black, Latine/x, and immigrant communities lived. As a result, credit eligible residents living in “risky areas” frequently couldn’t receive loans based solely on race or location. These maps were later known as “redlining maps.”

Now a new digital mapping tool launching February 16 makes it easier than ever to see how the history of redlining shapes communities today.

Over the last year, Greenlink Analytics translated the University of Richmond’s comprehensive archive of “residential security” maps into modern day census tracts and assigned a percentage based on a tract’s level of redlining. An important feature of the new tool is that people can see the impact and legacy of redlining in their neighborhood.

“We focused on redlining because we believe that bringing historical housing policy data into the Greenlink Equity Map, aka GEM, will help us understand their impact on how our communities are living today,” says Sharanya Madhavan, lead data scientist for the Greenlink Analytics redlining project, “Formerly redlined areas are associated with ongoing neighborhood segregation, wealth disparities, and the overall condition of neighborhoods.”

But seeing is believing. Take the City of Atlanta, for example. The redlining indicator shows that more than half of Pittsburgh, a predominantly Black neighborhood just south of Downtown Atlanta, was redlined (see image below of census tract 57). The site of the neighborhood was purchased by the Freedman's Aid Society in 1864 and founded by formerly enslaved people. But as the GEM tool also shows, what was once a flourishing corridor of Black-owned businesses is now plagued by severe energy burden (the percent of income spent on electricity and gas bills), lack of access to health insurance, and high housing burden (residents spending more than 30% on housing costs).

Nearby, the mostly Black community of Roseland had been almost a quarter redlined and is now situated near a penitentiary, located in a food desert, and blighted with old and abandoned houses. Like Pittsburgh, this neighborhood also suffers from severe energy burden, lack of health insurance access, and housing burden. As we can see with both neighborhoods, redlining helps contextualize a common pattern of historic disinvestment in non-white communities.

To generate these insights, Greenlink used the original HOLC redlining maps with their historic boundaries and risk categories and inserted them into a detailed digital map of the United States. The historic four risk-levels, A, B, C, or D, corresponded with the colors green for “best,” blue for “still desirable,” yellow for “declining,” and red for “hazardous.” Each census tract converts the risk categories into ratios based on the percent and grade of redlining assigned in the original maps.

The redlining indicator features approximately 202 cities and more than 16,000 neighborhoods across the United States. The Greenlink Equity Map displays over 40 environmental and social disparity measurements, including asthma rates, energy burden, heat intensity, and now redlining.

“One of our core commitments at Greenlink is to tackle systemic injustice,” says Madhavan. “We are hoping to do just that by helping people visualize redlining.”

To receive a demo of the redlining tool, or learn more about the Greenlink Equity Map, reach out to Angelica (Jellie) Duckworth ( or Daniel Wagner (


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