Spanish. Our local high school had about five or six Spanish classes in the grades where a foreign language was a required subject, and perhaps two French classes, and I don't remember the others.
Of course English is the predominant language in the United States, about 40 million people over the age of 5 speak Spanish at home. I would guess that where I live--in the Northeast, not an area you link of as heavily Latino--most supermarket store items carry labels giving the names in both English and Spanish.