Planes at Roosevelt Field, Long Island, New York  prior to  "Transcontinental Air Race of 1919" which saw 33 planes cross the U.S. with 8 completing the round-trip (out of 67 which began the trip).
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.