He is best known for his highly acclaimed biography of rock guitarist Jimi Hendrix, which Henderson revised and expanded for a second edition that was published in 2009.

Henderson became active in the many Black nationalist, arts and anti-war movements, upon moving to the Lower East Side of New York.

Henderson worked with the National Endowment for the Humanities, the Free Southern Theatre in New Orleans, and the Teachers and Writers Collaborative at Columbia University.

Later, he taught courses, seminars, and workshops at Long Island University, New York's New School and St. Mark's Poetry Project.

[3] Henderson spent more than five years researching, interviewing, and writing the biography Jimi Hendrix: Voodoo Child of the Aquarian Age, which was originally published in 1978.

Other notable editors and regular contributors to Umbra magazine include Tom Dent, Ishmael Reed, Brenda Walcott, N. H. Pritchard, Askia Toure, Lorenzo Thomas, Al Haynes and Calvin C. Hernton, among others.