Isabelle, I grew up in a small city in rural upstate New York State, and live in a rural area halfway between two metro areas in rural North Carolina.
Vacationers from la Belle Province would regularly take the 401 to the Thousand Islands Bridge, then Interstate 81 south through the States, stopping in my home town for meals, lodging, shopping, or whatever. Businesses felt no real obligation to have French-speaking staff – but those that did got the lion’s share of Quebec-origin traffic. (Yes, Canadians, I’m aware that Francophone does not equal Quebecois – but in this case, with extreme eastern Ontario Anglophone Loyalists, almost to a man in my childhood, and virtually no traffic from the Maritimes, it effectively does.)
In that city of 30,000 there were a sizeable number of families who spoke Greek or Italian within the home, and the Catholic church one block from my childhood home dropped their Mass with a homily in French (for the Francophone-immigrant families) the year I was born. We were 85 miles north and 90 miles south of Iroquois lands (Onondaga and Akwesasne, respectively) where English was standard but the tribal tongue was also preserved and used regularly.
Down here, I would guess that between 10% and 20% of the population in my immediate area – the “Five Counties” section where extremes of five counties meet – is of Mexican origin and uses Spanish as their in-home language. Many speak English either haltingly or not at all.
My experience with urban areas is many years in the past, aside from Raleigh, but they are traditionally cosmopolitan, with a variety of neighborhoods where languages other than English are spoken as a matter of course.
Fluency in a foreign language is valuable in academic careers, as you note – while probably 60% of technical papers and formal international publications in academic fields are today written in English, still a large part are written in French, German, and the authors’ national languages.
But even more significant is the fact that “the global village” is not merely some MacLuhanesque concept but a practical reality – I’ve tapped my halting Spanish more in the last five years, just to help folks in the grocery, place orders at bodegas, and so on, than I had in the previous thirty. Our church helped relocate Kosovar refugee families – and the one couple fluent in Shqipni had a workout. Ads for clerks, office staff, etc., regularly indicate that fluency in Spanish is a requirement or a plus towards hiring.
There are very practical reasons for children and youth being expected to learn a foreign language, and not merely for academic, college-prep reasons.