He is a descendent of Bishop Richard Allen (founder of the AME Church). Chief researcher, International Homophilics Institute (IHI) since 1966. Founder of IHI's Committee on Negro Homophilica, 1967, now IHI's Africa Committee.

Many of the historical names of African American on this list were first brought to academic and public attention by Coleman. He was an early correspondent of Mattachine and the One Institute and IHI's Encyclopedia Homophilica which provided base data for the Encyclopedia of Homosexuality, 1990.

In 1991 he served as Secretary of the American Historical Association Committee on Gay and Lesbian History . He has served as Editor of the Journal of Homophilics (1980-1990) and also as Editor of The Gay Review (1990-1991).