Between 1935 and 1940, federal appraisers graded thousands of urban neighborhoods A through D — green for "best," red for "hazardous." Lay those maps over the 2020 census grid and life expectancy, children's adult incomes, and homeownership still sort by the colors.
The Home Owners' Loan Corporation was a New Deal agency with a clerical task: tell lenders where mortgages were safe. Its field agents drew "residential security maps" for more than two hundred cities and shaded each neighborhood by grade. The forms they filled out scored housing stock and incomes — and, explicitly, the race and national origin of residents. "Infiltration of Negroes" was a standard reason to mark an area red.
The maps stopped being used decades ago. The agency itself dissolved in 1954. Almost no one living inside those boundaries today has ever seen them. And yet, when we overlay the digitized polygons on 2020 census tracts and ask how life is going inside each color, the grades read like a forecast.
Each panel below is one outcome, measured in the last decade, averaged over the people who live inside each 1930s grade today. Life expectancy steps down a year-and-change per grade. The chance a poor child climbs the income ladder steps down with it. Median household income drops by $56,000 from A to D; homeownership — the wealth machine the maps were built to direct — falls by half.
Averages hide the spread, and the spread matters: there are red-lined tracts where people now live past 85, and A-graded tracts that have fallen apart. Each dot below is one modern tract. The distributions overlap heavily — what the grades shift is the center of gravity. The median D tract today sits roughly where the bottom quarter of A tracts sits.
The left map is what the appraisers drew. The right map is how long people live there now. You do not need a statistical model to see the transfer — in Milwaukee the red north side of 1938 is the short-lived north side of 2015; in Nashville the gap between the green southwest and the red north quarter is twelve years of life.
The A-to-D life-expectancy gap is not the same everywhere. In 28 cities with enough graded tracts to compare, it runs from about three years (San Diego, Houston — where postwar growth scrambled the old map) to more than ten (Nashville, Louisville — where the 1930s boundaries still trace today's dividing lines almost exactly).
The appraisers did not pick neighborhoods at random. They drew red around places that were already poor, already crowded, already Black — so part of what the staircase shows is the persistence of disadvantage that predates the maps, not the maps' own effect. Economic historians who compare blocks just inside and outside the boundaries find real but more modest causal effects on homeownership, house values, and racial segregation that peaked mid-century and faded slowly after fair-housing law.
But for this book's purposes the distinction is almost the point. Whether the maps caused the sorting or codified it, the result is the same ledger: a child born today inside a line drawn ninety years ago — drawn with fountain pens, by men measuring "infiltration" — inherits a different life expectancy, a different chance of owning a home, a different rung on the income ladder. Few facts make the book's central claim — that place is accumulated history, wearing the costume of geography — quite this literally.