For this service, he received a Navy Letter of Commendation (awarded a Navy Commendation Ribbon, which was later updated to the Navy and Marine Corps Commendation Medal) from his commanding officer for "meritorious and efficient performance of duty as Officer in Charge of the South Pacific Combat Air Transport Command". Upon his return to the U.S., Nixon was appointed the administrative officer of the Alameda Naval Air Station in California. In January 1945 he was transferred to the Bureau of Aeronautics office in Philadelphia to help negotiate the termination of war contracts, and received his second letter of commendation, from the Secretary of the Navy[50] for "meritorious service, tireless effort, and devotion to duty". Later, Nixon was transferred to other offices to work on contracts and finally to Baltimore.[51] On October 3, 1945, he was promoted to lieutenant commander.[44][50] On March 10, 1946, he was relieved of active duty.[44] On June 1, 1953, he was promoted to commander in the U.S. Naval Reserve, from which he retired in the U.S. Naval Reserve on June 6, 1966.