Residential segregation by race grew sharply during the early twentieth century as black migrants from the South arrived in northern cities. Using newly assembled neighborhood-level data, we provide the first systematic evidence on the impact of prewar population dynamics within cities on the emergence of the American ghetto. Leveraging exogenous changes in neighborhood racial composition, we show that white flight in response to black arrivals was quantitatively large and accelerated between 1900 and 1930. A key implication of our findings is that segregation could have arisen solely from the flight behavior of whites.

This paper studies how the expansion of segregated neighborhoods eroded black wealth in prewar American cities. Using a novel sample of matched addresses, we find that over a single decade rental prices soared by roughly 50% on city blocks that transitioned from all white to majority black. Meanwhile, pioneering black families paid a 28% premium to buy a home on a majority white block, after which their homes lost 10% of their value. These findings strongly suggest that segregated housing markets cost black families much of the gains associated with moving north during the Great Migration.