Under his leadership, the company became one of the leaders of the commercial aircraft industry, engaging in a decades-long struggle for supremacy with arch-rival William Boeing and his eponymous enterprise.

He had been an early aviation enthusiast; at the age of 16 in the fall of 1908, he convinced his mother that he needed to witness the Fort Myer trials of the Wright Flyer.

He later built model airplanes, some with rubber-bands and other motors, in his dormitory room at Annapolis and tested them on the grounds and in the academy's armory.

Shortly after Glenn Martin merged with Wright Company to form Wright-Martin, Douglas resigned to become, in November 1916, the chief civilian aeronautical engineer of the Aviation Section of the US Army Signal Corps.

[11][12] In March 1920, Douglas resigned from his $10,000 (equivalent to $152,000 in 2023) a year job to return to California, where he had met and, in 1916, married Charlotte Marguerite Ogg (1892–1976).

[14] Donald Douglas was not only a very highly regarded engineer and bold entrepreneur, but as World War II approached, he proved to be remarkably prescient.

Douglas Aircraft grew from being a small company with 68 employees in 1922 to being the fourth largest business in the United States.

As William S. Knudsen of the National Defense Advisory Commission observed, "We won because we smothered the enemy in an avalanche of production, the like of which he had never seen, nor dreamed possible."

[24][25][26] A bust of Douglas, and a commemorative plaque for him is located at the Scott Air Force Base in St. Clair County, Illinois.