His younger brother Jonathan Paul was born in 1941 and died in a motorcycle accident in 1977. His younger sister, Katherine Winifred, was born in 1943. They grew up in Bedford-Stuyvesant, a north-central portion of Brooklyn, until his family moved in 1951 to their homestead in Los Angeles, where he attended Dorsey High School. As a teenager, Harper was eager to get out of his father's house and into his own, marking his desire to work, create and learn on his own terms.