With a degree in mathematics and a Navy correspondence course on cryptology Wilma Davis was hired to work in the Army's Signal Intelligence Service in the late 1930s. Her first assignment was with the Italian diplomatic codes which she exploited until 1942 when she transferred to the Japanese problem. Within two years she was the head of the department that solved and processed intercepted Japanese Army code messages. At the end of the war she moved on to the Chinese team and then to the Venona Project trying to break Soviet messages.
Ms. Davis left the cryptologic field a few times during her career but she could not stay away. She returned to work on Venona and returned a second time during the Vietnam War finally retiring in 1973.