Would be interesting to see this chart for Detroit. The City of Detroit (everything south of 8-mile) is around 90% black. One of the newspapers there analyzed census data for the 5 largest suburbs, and out of a total population of 500,000 they could only identify about 5000 black families. Those are Apartheid South Africa type numbers.
Interesting article on Detroit :
http://www.nytimes.com/2010/06/21/us/21detroit.html?_r=1
TITLE : RAZING THE CITY TO SAVE THE CITY.