Joseph Robertson was born in Harlem. He is married to Martha and they have had two sons. Their first son, Patrick Henry Robertson, died when he was only six months old. Their second son, Randy, is divorced. Growing up in a working-class family and being a member of a racial minority, Robertson seemed to sympathize with the downtrodden, including Marvel Comics' mutants, and he preached tolerance. He was forced to practice what he preached when his son came home from college with his white Jewish wife, Amanda.