Should English be declared the official language of the United States?

I didn't know that English wasn't already the official language of the U.S till i did a research on this blog. I always assumed that it was the official language.
YES! English SHOULD be the official language of the U.S, because

I think what is culturally insensitive is to live in another country and never learn the language. There has to be a common language that everyone can communicate.