This map will upset some people.
Business Insider: One Map That Shows Why English Will Never Be The Official Language Of The U.S.
US Census: Language Use in the United States: 2011
Obviously, the second language is Spanish. I have no problem with Spanish, or any other language. I speak some Spanish, and would like to learn more.
My problem is with people who move to the United States and refuse to learn English. Refusing to learn the dominant language of the area in which one resides is simply stupid. I have little patience for stupidity.