John G. Zinn was born on December 12, 1946 in Teaneck, New Jersey. He grew up in Wayne, New Jersey and graduated from Wayne High School in 1960.
From 1964 to 1968, Zinn attended Rutgers College, where he majored in business. Zinn became involved in managing the basketball teams, first managing the freshman basketball team under Coach Bruce Webster and then managing the varsity basketball teams coached by Bill Foster. In his interview, Zinn describes the 1965-1966 Rutgers basketball season and then the legendary 1966-1967 season in which Bob Lloyd and Jim Valvano led the Rutgers basketball team to a Final Four appearance in the NIT Tournament. Additionally, Zinn participated in ROTC for all four years of college, preferring to be an officer to potentially getting drafted after college.
Zinn attended graduate school at the Rutgers Graduate School of Business in Newark. In 1970, he earned his Master of Business Administration.
After graduate school, Zinn served in the Quartermaster Corps of the U.S. Army from 1970 to 1972. Zinn was stationed at Cam Ranh Bay in the Quartermaster Office of the 54th General Support Group as an assistant adjudant in 1971-1972. He was awarded the Bronze Star.
Zinn went on to a career as vice president of Fidelity Union Bank and Chief Financial Officer of the Episcopal Diocese of Newark. He has written books about the Civil War and baseball.