Racial segregation remains a problem in America, and it's lasting longer than anyone expected.

Just how bad things are can be determined through analysis of 2010 Census data.

The average black person lives in a neighborhood that is 45 percent black. Without segregation, his neighborhood would be only 13 percent black, according to professors John Logan and Brian Stults at Brown and Florida State.

Logan and Stult evaluated segregation in major cities with a dissimilarity index, which identifies the percentage of one group that would have to move to a different neighborhood to eliminate segregation. A score above 60 on the dissimilarity index is considered extreme.

In the following slides, we have ranked the most segregated cities in ascending order. They are illustrated with maps of cities by race created by Eric Fischer and publicly available on Flickr. The red dots show white people, blue is black, orange is Hispanic, green is Asian, and yellow is other.