The Thomas-Morse Scout, built in Bath, New York, was an advanced trainer, operated by the both the U.S. Army and the U.S. Navy. The aircraft became the favorite single-seat training airplane produced in the U.S. during World War I. The example on display in the museum, Army serial number 38899, had slightly over 20 hours of flight time when it was given civil registration 3991, later NC3991. It was donated to the EAA Aviation Museum from its owner, Allen Johnson of The Woodlands, Texas in March 2018.