 Besides writing for "The New Masses" and "Marxism Today", Selsam was an editorial board member for the Marxist journal "Science & Society", and he was a founder of the American Institute for Marxist Studies.Selsam had correspondence with prominent intellectuals and writers, including historian and civil rights activist W.E.B.Du Bois

Selsam married Millicent Selsam, a botanist and high school teacher

During his last years Selsam had a heart ailment., and he died in New York on September 7, 1970.