Actually my friend princedriss is technically correct as per my reading below:
The variety of English spoken in the United States is known as American English. English is the de facto national language of the United States, with 80% of the population claiming it as a mother tongue, and some 95% claiming to speak it "well" or "very well". 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, 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.
