The US is one of the least multilingual countries that I have lived in. It is very difficult to live in the US without speaking English. However, as the number of Spanish speaking people in the US continue to increase, I suspect that
Spanish will become a required subject in all schools and like it or not, the US will become bilingual.
(My bold)
Not a required subject - although it would help with understanding & using pre- and suffixes much as Latin used to. Spanish would usually be a more useful language in the US, especially in the larger cities and in many of the medium cities as well. As Spanish-speakers continue to move out of the larger cities, Spanish will be spoken in more and more rural areas too.
It's kind of a race - the 3rd & succeeding generations of Spanish-speaking descent tend to speak better & better English. But media offerings in Spanish - radio, TV, print - continue to accelerate as they find a market for a lot of consumer goods. That's the same reason that big-box stores - Walmart, Sears, K-mart - include Spanish with English instructions on product manuals. (Other languages also appear - French, German, Japanese - but Spanish is the not-so-foreign language that shows up the most, in my experience.)
As there isn't an official language @ the federal level, I suspect that Spanish will simply become a
de facto second language.
Ça va!