Cold Spring Harbor, New York
Simpson was born in 1957 in Freeport, New York. He grew up in Seaford, New York, and Cold Spring Harbor, New York. Educated at the Phillips Exeter Academy, he graduated in 1975; four years later he graduated from the University of Virginia. Receiving his M.A. in history at the University of Wisconsin–Madison in 1982, he earned his PhD in 1989.