One day Stevens was approached by the dean of students, an undercover recruiting agent for the U.S. Navy, to take a correspondence course in cryptography. Over the semester he progressed to the point that the Navy notified him that he had qualified for a commission. On Dec. 6, 1941, Stevens went to the Great Lakes Naval Training Center in North Chicago, Ill., to fill out the paperwork. The Japanese bombed Pearl Harbor the following morning.
After a brief posting to Washington, D.C., Stevens was sent to Pearl Harbor, where he spent most of the war as a cryptologic/intelligence officer. He was part of a code-breaking team working on Japanese intercepts. The group's efforts uncovered information that led to the shooting down of a plane carrying the Japanese architect of the Pearl Harbor attack, Adm. Isoroku Yamamoto, in 1943.