William L. "Billy" Mitchell, aged 56, died on February 19, 1936. He was an American Army Brigadier General who was a pioneering advocate for air power in the early 20th century. He helped transition the United States Army Air Service from an embryonic fighting force to a full-fledged service arm of the military. Mitchell was vocal in advocating for a fully independent Air Force and pushed for greater investment and commitment to aviation-related defense in the U.S. Prior to joining the Army, Mitchell was an aide to Gen. John J. Pershing who commanded American Expeditionary Forces in Europe after World War I. Mitchell is remembered for his role in creating the Army Air Service and for his advocacy for air power in defense of the United States.