He served in the United States Army during World War I before moving to Klamath Falls, Oregon where he established himself as a businessman.

He was the owner of successful automobile dealerships and three radio stations in the Klamath Falls area.

[1] Cornett served in the Oregon State Senate from 1941, to 1947 representing the 17th legislative district.

"[3] Pilot Cliff Hogue perished as well, when his small plane crashed in stormy weather southwest of Dog Lake.

[4] Marshall Cornett's remains were interred at Macedonia Cemetery, Burning Springs, Kentucky.