Eric Fischer’s racial demographic maps, derived from census data, are a great data visualization for anyone interested in race in America. For instance, here is the map of Chicago. Red dots are whites, blue dots are blacks, green dots are asians, and yellow dots are hispanics.
Here’s New York:
There are many more. You can draw lots of generalizations just by looking at a sampling of these pictures. For instance, you regularly see a fair number of whites mixed in a predominantly hispanic neighborhood, but you rarely see the same in a black neighborhood. No prize for guessing why.