Why do minorities in the US refer to themselves as a hyphenated American?

Or do they? Perhaps I am mislead by the media but I see the term African-American, Mexican-American, Iraqi-American etc. Personal opinion sure but I don’t refer to myself and an English-American. I call myself American dammit. What about you?

I know in the past that we had Irish-Americans and Norwegian-Americans but we no longer differentiate.
Is that all it takes, time? Or do you have to demand and force the nomenclature?