Parachute Testing at McCook Field, Ohio, 1922.  Capt. Albert W. Stevens carried an oxygen flask when he jumped from 24,000 feet after conducting photographic experiments at Dayton, Ohio, on June 12, 1922.
United States Air Force
Maurer Maurer, 1987, Aviation in the US. Army, 1919-1938, United States Air Force Historical Research Center, Office of Air Force History,  United States Air Force, Washington, D.C.