Aaron Swartz is born in Chicago to William and Susan. He has two younger brothers, Noah and Ben.

Swartz paternal grandfather, William Swartz, was a multimillionaire businessman and founding director of the Albert Einstein Peace Prize Foundation.

William Swartz, who died in 1987 at age 75, was active in the nuclear-disarmament group Pugwash Conferences on Science and World Affairs, which won the Nobel Peace Prize in 1995. He also served as a director of the Bulletin of Atomic Scientists, a Chicago-based magazine that calls out threats from nuclear weapons, climate change and emerging technologies in the life sciences.

Though Swartz attended North Shore Country Day School, a small private school in Winnetka, he became a teen-aged proponent of “unschooling.” He left high school during his freshman year to study on his own at home.