Once upon a time, not so very long ago, the study of Africa in the United States was a very rare and obscure practice, engaged in almost exclusively by African-American (then called Negro) intellectuals. They published scholarly articles primarily in quite specialized journals, notably Phylon, and their books were never reviewed in the New York Times. As a matter of fact, at this time (that is, before 1945) there weren't even very many books written about African-Americans in the U.S., although the library acquisitions were not quite as rare as those for books about Africa.