Walking around the north side of Philadelphia’s University City neighborhood, it’s difficult to imagine what stood before the sprawling University of Pennsylvania medical campus, replete with scores of half-empty parking lots and franchise restaurants. But for Segregation By Design, a new initiative that seeks to unearth the legacy of racist planning in American cities, the visual history is clear. What stood before University City was Black Bottom, a thriving Black working-class community whose proximity to Philadelphia’s urban core made it a prime target for the 1950s slum clearance, freeway construction, and redevelopment projects that decimated hundreds of low-income neighborhoods across the country.