If you hold dual citizenship in the country of Africa and the country of America then you can call yourself African-American.

Since there is no country called Africa you can't call yourself African-American.

The closest thing to African-American is if you hold dual citizenship in the country of South Africa and the country of America then you can call yourself South African-American.

If you only hold citizenship in the country of America, then you are American, not Asian-American, not African-American, nor any other stupid thing you want to call yourself.