They are really American Africans, but for some reason they frown on being called that.
About 2/3 of Blacks, I know, dislike being called African-Americans. They know that, since a dictionary definition of African is a resident of Africa, an African-American is anyone who was born in Africa, immigrated to the U.S., and became an American citizen. This definition includes a few races, so whether someone is an African-American cant be determined by his or her skin color.