Residential segregation measures the physical separation of population groups into different areas (i.e., neighborhoods) in a geographic unit (i.e., a county or city). We report the index of dissmilarity ($D$) for United States counties in our data file. The index of dissimilarity is a measure of evenness and measures the proportion of a group's population that must move so that each sub-county geographic unit in a county has the same proportion of that group as the county. We use census tracts as our sub-county geographic unit because census tracts nest within counties. $D$ is typically calculated using two population groups. We have computed the residential segregation measure for the following groups: White alone:Black alone White alone:Asian alone* White alone, not Hispanic or Latino:Hispanic or Latino