THE CHANGING GEOGRAPHIC STRUCTURE OF BLACK-WHITE SEGREGATION IN THE UNITED-STATES

Objective. The goal is to measure black segregation at four geographic levels-state, county, city, and neighborhood-to assess the changing g eographic structure of segregation in the United States from 1900 to 1 990. Methods. Data from the decennial U.S. Census are used to measure the level of black-white segregation at each geographic level using di ssimilarity and isolation indexes. Results. A long-term trend away fro m macro-level segregation toward microlevel segregation is documented. Whereas state-level and county-level segregation indexes fell from 19 00 to 1970, neighborhood-level indexes rose. Beginning around 1950, mu nicipal-level segregation began to increase as well, yielding a geogra phic pattern in which blacks and whites increasingly live in different cities as well as different neighborhoods. Conclusions. Throughout th e twentieth century, segregation patterns have consistently evolved to minimize white contact with blacks; the only thing that has changed i s the level at which the segregation occurred.