James H. Howard was a Naval Aviator who resigned his commission in 1941 to join the Flying Tigers of the Republic of China Air Force. As such, he became an ace in China with six victories. Shortly thereafter, the former military pilots of the Flying Tigers were offered U.S. Army commissions to fly with the Army Air Forces. Howard accepted and became a Captain in the USAAF. He ended up flying the P-51B Mustang in Europe and won another six victories in that theater.
Captain Howard was the only fighter pilot in the European theater to earn the Medal of Honor in World War II.
He went on to postwar service in the USAF Reserves, ending up as a Brigadier General.
https://en.wikipedia.org/wiki/James_H._Howard