Finding Suburbia in the Census

What exactly is a suburb—and why has it been so hard to define? This research from the U.S. Census Bureau dives deep into that question, introducing a new method for classifying American communities beyond the urban-rural binary. By using housing unit density and consistent historical geography from 1940 to 2020, it traces how suburban, exurban, and rural landscapes have evolved around urban cores. The result is a richly detailed portrait of how the U.S. has spread out, grown up, and reshaped its residential identity over eight decades.