Ben Blatt created the two maps below (and a few others) for Slate.
One of the most interesting data sets for aspiring mapmakers is the Census Bureau’s American Community Survey. Among other things, that survey includes a detailed look at the languages spoken in American homes.
One thing he discovered was that Spanish is the second most common language spoken in all but seven of the 50 U.S. states. Take out Spanish and the nationwide picture is quite a bit more diverse.
At Slate, Blatt spotlights three other language maps.