Gulf of America

Optimus Prime said
Honestly I would probably say America myself

If United States is the correct answer what are its citizens called?

Because it shouldn't be Americans

US citizens. I do real estate signings and the Patriot Act requires proof that you are a "United States citizen"

Yes, it's all kind of splitting hairs. It's easier to say "I am an American," and overseas you are like to be asked if you are an American.