Douglas O-31B

Photograph of a United States Militia Bureau Douglas O-31 aircraft parked at an airfield, likely at the National Air Races in Ohio, circa 1930s.

Inscription: "U.S. Militia Bureau. Douglas O-31B."

Inscription on verso: "Douglas O-31B Conqueror 650 M20LM."

Inscription underneath photograph on album page: "O-31B F."

Item from page 23 of the LeRoy Milliren National Air Races photograph album, circa 1920s-1930s. Album contains one hundred ninety-eight (198) black-and-white photographs taken at the air races during this time period.