The Census Bureau, using American Community Survey data, has an interesting mapping tool of languages in America. Above you find the map for people who say they speak Spanish and who rate their English proficiency below the "very well" level. Each dot is 100 people. And you can see that even though the bulk of the Hispanic population lives in a handful of states, immigration from Latin America really has touched essentially the entire country. The blank spots on the map tend to come in places where the overall population density is very low. Essentially all major population centers feature Spanish-dominant individuals.
French dominance, by contrast, is quite rare and distributed in a way that's well at odds with the aggregate population distribution of the United States:
There are more French-dominant individuals in Maine (where the ties to the Francophone population in Québec run deep) than in Seattle, and the French-dominant population of Louisiana looks bigger than the French-dominant population of California. Aside from those Acadian populations, immigration from Haiti and the Francophone Caribbean seems to be a driver of facility with French.
And then there's Italian:
If you want to know why I'm skeptical of TripAdvisor's claims that San Diego and Las Vegas are America's top pizza towns, just check out this map. You can clearly see the Northeast corridor's pizza belt on this map, as well as the origins of Chicago's robust rogue pizza culture of its own. It also makes me curious about pizza availability in south Florida. Italian-dominant individuals in the United States are probably overwhelmingly elderly at this point (especially in Florida) and not actually making pizza, but to the extent that pizza skill follows the customer base, I'm intrigued.