I decided to do a map very similar to
Retromike's on Hispanic population, except its language other than English that is spoken at home (many of these people can speak 2 or more languages) by county. Its in 30%, 50% and 70% incriments with light blue being 30-49.9%, dark blue being 50-69.9%, and purple being 70% or more. These numbers are straight from the census bureau
Disclaimer: I did not actually check every county, but I did check many. Basically I did check every county in the west, but once I got to the south and midwest I only checked a few (urban and higher than 20% minority counties) I made assumptions based on the following things:
urban/population dense centers
% Hispanic, Asian, Native American
Proximity to borders
If I missed a county, let me know.
What I noticed:
Rural Hispanic heavy counties (like those in Texas and Kansas) are more likely to speak another language (Spanish) at home than urban Hispanics and suburban Hispanics. These are likely counties full of jobs that black and whites are less likely to do, so they immigrate to those areas in search for work. They are more likely to be first generation immigrants than say, those near the Mexican border.
In general, this demographic correlates well with Hispanic and Asian population (which is why I did it the same way Retromike did it). Though in other instances other ethnicity and groups that are white need to be considered (French in Cajun country, Amish in Indiana/Ohio).
Native Americans in the Plains speak mainly English, in Arizona/New Mexico they speak other languages.