He prepared at Lake Forest (Ill.) High School, where he was active in publications, dramatics, and orchestra. At Princeton he majored in mathematics, where he held a research assistantship, joined Prospect Club, and was personnel director of The Daily Princetonian. He later served as alumni secretary of Prospect Club.

Jack married Diana Standahl in 1957, earned a Ph.D. in mathematics at the University of Chicago in 1961, and was professor of mathematics at the University of Minnesota for 33 years. His life had many passions, including education, opera, and skiing. He is remembered as a loving father, educator, and intellectual.

Predeceased by his wife of 60 years, Diana, Jack is survived by his sons, Leonard, Chris and Mark; nine grandchildren; and two great-grandchildren.