May 15th, 1937. A Saturday, eight decades in the past. Another map is being drawn. With a straight edge, the map-maker marks out a kind of geometric jigsaw puzzle onto the city and then he fills each piece, one by one, with a color. Green, blue, yellow green. First Grade, Second Grade, Third Grade, Fourth Grade. This rainbow-ed map of St. Louis is one of hundreds of similar maps of cities that are being made across the nation, in the wake of the Great Depression, with the support of The Home Owners Loan Corporation. The HOLC, recently born of the New Deal, has a remit to re-finance mortgages that are currently in default, in an effort to avoid foreclosure and thus to offer a lifeline to failing cities. Maps like the one being drawn are to act as guides to HORC officials, showing in which areas of the city they should offer support, and in which ones they shouldn’t.

As we watch, this 1937 map-maker colors in a polygon with green, just to the North of the city’s sprawling Forest Park. The people who are lucky enough to live in this First Grade polygon will very likely get government money. They’ll keep their homes. A few minutes later, the map-maker shades in another region with red. Fourth Grade. Under the shade of these red lines, the people will get no money from HORC, no support in the face of their mounting debts. At worst, they’ll lose their homes; at best they’ll become more deeply entrenched in financial despair.

Residential Security Map of St. Louis, 1937. Commonly known as a red-lining map.

We know now that the HORC’s maps were racist instruments, half-heartedly hidden under ideas of renewal and ‘residential security’. Red-lined areas were almost always African American neighbourhoods, and these maps became tools to deny black people property rights, to force them out of home ownership, to remove them from real-estate based capital systems and thus from civic discourse. Those map-makers, on that May day in 1937 were setting out a vision for the future of their city — their own white future, a new map of their own white city.

Map Room Facilitator Emily Catedral walks the students through a series of data layers, projected precisely on top of their map.

Back in the gymnasium, the students are gathered around the edge of their finished map. The project’s facilitator, Emily Catedral, is showing them how they can use an iPad interface to project dozens of data layers on top of the map they’ve drawn. She walks them through some data gathered and scraped from census records and city data repositories — employment rates, property values and annual income. Traffic, and pollution. The number of no-car households. Distance to primary care facilities. The students notice quickly that, although each of these map layers show a different thing, they have a similar visual pattern, a kind of houndstooth shape that shows up in every map.

Then Emily taps the iPad and projects the red-lining map from 1937 on top of the map they’ve made today. The students see their own neighbourhood as those map-makers saw it eighty years ago. It takes a few minutes for them to decipher the key, and then they find it: there is that same shape! Indeed, they realize, this red-lining map was still present in almost every map they’ve looked at. Sometimes its edges were faded a little bit, but there it was, again and again.

Left: Unemployment levels, 2016. Right: 1937 red-lining map.

“The historical map that showed home loan ratings was very powerful because kids understand that the A neighborhoods are still filled with big beautiful houses — and white people,” said the teacher, Anne Cummings. “The D ratings I could identify as historically black neighborhoods and could speak to the fact that the one near my home was considered blight and claimed through eminent domain. There’s a Menards there now, that my family and others have boycotted.”

This connection– between the current conditions of their neighbourhood and the racist policies of the 1930s– wasn’t the only one the students found during their time in the Map Room. “We used the bus route overlay and the one about households that own cars to talk about the lack of crosswalks on one of our major thoroughfares,” Cummings told me. “It’s just south of our district’s poorest elementary school, and people are often hit or nearly hit.” The students also spent time comparing maps showing healthcare enrollment and asthma prevalence, once again overlaying this information on top of their own map to help find themselves and their daily lives in the data.

Over the course of five weeks, thirty other groups made 10 foot by 10 foot maps in the gymnasium. Forward through Ferguson, a organization who is looking to promote avenues for lasting change out of The Ferguson Report, made a map showing the drastic difference in life expectancy between black and white communities in the city. Gateway Greening mapped out every community garden within the City of St. Louis. Team TIF compared the city’s LRA properties to tax abatements, challenging the commonly heard assertion that these abatements are being used to incentivize development in ‘blighted’ areas. Many of the mappers chose to render their personal stories onto their maps, marking places that held meaning to them, offering anecdote and emotion to go alongside statistic. A map showing Christian churches is densely annotated: “I am the first in my family to graduate college,” someone has written beside the Ministerio Apostolico Plantio Del Señor. “I NEVER thought I could get a Masters degree, let alone a Doctorate.”