[2] Beginning in 1918, Fleming taught at and headed Columbia University's School of Military Cinematography, training over 700 soldiers to cut, edit, shoot, develop, store and ship film; filmmakers that participated in the program included Josef von Sternberg, Ernest B. Schoedsack, and Lewis Milestone.

In the opinion of veteran cinematographer Archie Stout, of all the directors he worked with Fleming was the most knowledgeable when it came to camera angles and appropriate lenses.

Red Dust (1932), Bombshell (1933), and Reckless (1935) showcasing Jean Harlow, while Treasure Island (1934) starring Wallace Beery and Captains Courageous (1937) with Spencer Tracy brought a touch of literary distinction to boy's-own adventure stories.

He directed Clark Gable in a total of five films – Red Dust, The White Sister, Test Pilot, Gone with the Wind, and Adventure.

[9][10][11] Frequent guests to his estate included Clark Gable, Vivien Leigh, Ingrid Bergman, and Spencer Tracy.

Despite mixed reviews, Fleming's film version of the life of Joan received seven Oscar nominations, winning two.

It was reported in James Curtis's book Spencer Tracy: A Biography[13] that Anne Revere once said Fleming was "violently pro-Nazi" and strongly opposed to the United States entering World War II.