Khalil Gibran Muhammad, in Wiseman's
Ex Libris: New York Public Library. I went to high school with KG, and we both worked in the same small computer shop for several years as our first jobs. He was the director of the NYPL's Schomburg Center for Research in Black Culture at the time this movie was shot, now he's a Harvard professor. Probably the smartest guy I know personally (though to be honest I haven't seen him in some 30-ish years).
He also appears in
The 13th.