Are you ignorant?
American is synonymous with US citizen.
Hispanic American refers to US citizens of Hispanic background.
Whether American should be synonymous with US citizen is a separate issue.
I guess it depends upon where you went to school. It's never meant exclusively a US citizen in my LONG life.
Tell me, what country does European mean? Russian? (made up of many countries which float in and out of the soviet empire) and many other examples.
I guess you can call me ignorant if you think that an alum of UC Berkeley (when it was the premier University in the country that a woman could attend) as well as Cardinal Strich University. (magna cum laude) qualifies as “ignorant”.