They had recently received the Thomas-Morse MB-3, and asked B Douglas Thomas to modify two of them to be racers.

It took part in the 1921 Pulitzer Trophy race, but during the race its fuel pump malfunctioned and it crashed and was destroyed by fire when a lighted match by a souvenir hunter ignited the fuel.

It competed for the US Navy in the Pulitzer Trophy on 14 October 1922.

Piloted by Captain Francis Pat Mulcahy it withdrew after 30 minutes with an overheating engine.

Media related to Thomas-Morse MB-7 at Wikimedia Commons