Languages of the United States
http://en.wikipedia.org/wiki/Languages_of_the_United_States
Excerpt:
English is the de facto national language of the United States, with 82% of the population claiming it as a mother tongue, and some 96% claiming to speak it "well" or "very well".^[3] However, no official language exists at the Federal level. There have been several proposals to make English the national language in amendments to immigration reform bills,^[4][5] but none of these bills has become law with the amendment intact. The situation is quite varied at the State and Territorial levels, with some states mirroring the Federal policy of adopting no official language in a de jure capacity, others adopting English alone, others officially adopting English as well as local languages, and still others adopting a policy of de facto bilingualism.