In 1952, Carter began an association with the US Navy's fledgling nuclear submarine program, then led by Captain Hyman G. Rickover. Rickover's demands on his men and machines were legendary, and Carter later said that, next to his parents, Rickover was the greatest influence on his life. At the time of President Kennedy's assassination, Carter was informed by a customer of his peanut business of the killing, prompting Carter to remove himself from work and sit alone. Carter later called the assassination 'the greatest blow that I had suffered since my father died.' Carter later called the assassination 'the greatest blow that I had suffered since my father died.' 'Carter Nominated, Names Mondale Running Mate'. Toledo Blade.