A term wrongly used to give identity to, any black person in America.
African American was actually meant to give an ETHNIC identity to blacks who are descendants of (Black) African slaves who were brought to the United States. This term excludes Black Jamaicans, Nigerians, Kenyans, Black Dominicans,etc.....
SOME Whites, and sometimes other non-blacks are afraid to call us black, so in any professional setting they will say African American. Other whites claim it's unfair, because they won't get called European American, but really it's the same thing as calling whites from Italy Italian, and Asians from China Chinese. Hell nobody complains about East Asians being called Asian, even though not all Asians are of the same race.
Most African Americans can not trace our African roots back to any particular country/tribe so Africa is used, as the substitute.
Oh and that guy who said it more offensive to be called AA than N*gger is a complete dumbass
Bob: Barack Obama is the first African American president
Terrance: Nope, he's the first Kenyan American president.