
It’s a nationality with unique subcultures and ethnicities within it. I strongly believe that any ethnicity should be able to be any nationality. This is why I don’t like it when a country is named after its dominant ethnicity, because then people not of that ethnicity are treated as lesser.
But there are cultures that are uniquely American. Anglo-American culture is distinct from British culture. African-American culture is a unique ethnicity formed by the history of slavery. Cajuns, Gullah, Louisiana creoles, and our immigrant subcultures (ex Irish American, Italian American, Jewish American) are distinctly American. And native Americans of course.