Considered the father of the United States Air Force, William "Billy" Mitchell was famous for his visionary ideas on military strategy and his impolitic actions that led to a demotion and eventual court-martial. Mitchell first volunteered for military duty in 1898 and served in Cuba, in the Philippines and along the Mexican border. In 1915 he left the General Staff for the aviation section of the Army Signal Corps and was sent to Virginia, where he learned to fly by 1916. When the U.S. entered World War I in 1917, Mitchell became the air officer for the American Expeditionary Forces (AEF) led by "Black Jack" Pershing
. Mitchell served with distinction during the war and proved the importance of air support of ground troops, as well as the strategic value of air raids across enemy lines. He returned to the U.S. a brigadier general in 1919 and was named the assistant chief of the Air Service. Charged with organizing and training a diminished service, Mitchell became a fierce advocate for a separate air force, but ran afoul of the Navy establishment with his boasts that airplanes made battleships obsolete. In the 1920's he famously demonstrated that airplanes could, indeed, sink a battleship, and predicted that the U.S. was vulnerable to an air attack on Hawaii by the Japanese. His zeal, and his talent for getting headlines, only frustrated his superiors, who demoted him to the rank of colonel and sent him to Texas. It may have been a slight stain on his military record, but the demotion didn't shut him up. After the Navy's airship Shenandoah
crashed in September of 1925, Mitchell publicly accused the Navy and War Departments of incompetence and "criminal negligence." Mitchell was court-martialed and convicted of insubordination, but rather than serve a sentence of a five-year suspension, he resigned his commission in 1926. From his retirement in Virginia he continued his crusade until his death. Generally considered vindicated in his vision despite his flaws, he has an honored position in the history of U.S. military air power.