He has published ten books of poetry, two of which - Dear John, Dear Coltrane and Images of Kin - have been nominated for the National Book Award. A great deal of his poetry is influenced by jazz and history. Many of his poems have been included as important examples of African-American literature and jazz poetry in various anthologies. Harper often writes about his wife, Shirley, their children, and their ancestors, as well as friends and various black historical and cultural figures.