He prepared at Lincoln High School in Portland. Upon graduation Jack received one of 19 scholarships Princeton offered that year to boys from Western and Southern states. At Princeton he majored in the School of Public and International Affairs, lettered on the varsity fencing team, edited poetry for the literary magazine, and graduated with honors. He was a member of Dial Lodge. 

During World War II, Jack served with distinction in Europe as an Army officer in the 310th Field Artillery Battalion. He served in campaigns from Normandy to V-E Day. Jack received a battlefield promotion to captain, was awarded the Bronze Star, and his battalion received a Presidential Citation. 

Jack practiced law in Portland. In 1970 he was appointed to the bench for the county circuit court, where he served 14 years. Upon retirement, he was active in local politics and in a variety of civic affairs. In his spare time, he wrote novels, poetry, and an autobiography, The Politics of Public Ventures, published in 2010.

His first wife, Clarissa Hagar Beatty, predeceased him, as did his second wife, Virginia Rupp. Son John C. Beatty III ’69 died in 2020. Daughter Clarissa Jean Beatty and grandson Trask John Beatty-Pernetti survive him.