Kennedy was born in Florida and studied mathematics at several universities. From 1961 he was professor of mathematics, with research interest in the history of mathematics, at Providence College (Rhode Island), He spent three sabbatical years doing research in Italy and Germany.
Kennedy came out as gay on the cover of the magazine The Cowl, and, along with Eric Gordon, was part of the first Gay Pride parade in Providence, Rhode Island, which was held on June 26, 1976.
In 1986 Kennedy moved to San Francisco, where he continued his historical research, now in the beginnings of the gay movement in Germany. Since 2003 he has been in a home for assisted living in Concord, California. He has over 200 publications in several languages, from an analysis of the mathematical manuscripts of Karl Marx and a revelation of Marx's homophobia, to theoretical genetics and a proof of the impossibility of an organism that requires more than two sexes in order to reproduce. In addition, Dr. Kennedy has written biographies of the Italian mathematician Giuseppe Peano and the German homosexual emancipationist/theorist Karl Heinrich Ulrichs, and has edited the collected writings of Ulrichs. His translations of the boy-love novels of the German anarchist writer John Henry Mackay and his investigations of the writings of Mackay have helped establish Mackay's place in the gay canon.
Hubert Kennedy, 1994, by Robert Giard (http://beinecke.library.yale.edu/dl_crosscollex/brbldl_getrec.asp?fld=img&id=1121498)
American photographer Robert Giard is renowned for his portraits of American poets and writers; his particular focus was on gay and lesbian writers. Some of his photographs of the American gay and lesbian literary community appear in his groundbreaking book Particular Voices: Portraits of Gay and Lesbian Writers, published by MIT Press in 1997. Giard’s stated mission was to define the literary history and cultural identity of gays and lesbians for the mainstream of American society, which perceived them as disparate, marginal individuals possessing neither. In all, he photographed more than 600 writers. (http://beinecke.library.yale.edu/digitallibrary/giard.html)