This marvellous map has a dot for each American, and each dot is colored blue, red, green, orange or brown for race, respectively White, Asian, Black, Hispanic, or other, including Native American, as per the US census. I live in very mixed town in a rather mixed State, but I was surprised at how segregated even my own town (Las Cruces, NM) is. My own neighborhood is mainly orange, with a strong blue presence, but some areas of the town are almost all orange and the wealthier neighborhoods mostly blue with a good dusting of orange and a dash of red. Our greens - yes, we have a few - are harder to find than Waldo.
I was pretty shocked, nonetheless, when I looked at a few American cities. They seem as ghettoized as if the Tsar had drawn the lines himself.