Produced by Disney in 1942, "Food Will Win the War" was a propaganda film of the Agricultural Marketing Administration, under the auspices of the United States Department of Agriculture. Narrated like a newsreel, the cartoon illustrates the might of American agriculture, in brilliant technicolor.
Like many propaganda films and newsreels from World War II, this one has plenty of bombast, with good and evil portrayed in stark black and white terms (even though the animation is in color). Released to American audiences on July 21, 1942, it had several goals. One was to buoy American confidence in food supplies. There were concerns that the U.S. was shipping too much produce overseas and that there would be shortages at home. These concerns were not unfounded, but wartime production increased enough that even though rationing eventually grew tight, everyone had enough to eat. Another was to impress upon foreign audiences that American production capacity was overwhelming and would strengthen the Allies, who had been at war for over two years already.
In 1941, Disney was suffering major financial losses from Fantasia - it was a box office flop and made just a fraction of what it cost to produce. You can see the economy of animation in many of the scenes of this film - where largely still images move across the frame or zoom in or out - achieved by layering cells.
But the success of Disney's animated films for the war effort helped keep the studio afloat during the war. They became well-known in particular for training films, as Disney animators were able to illustrate in fine detail mechanical operations and theoretical scenarios that would be difficult or impossible to film in real life. Some speculate that without World War II, Disney Studios might have gone under after only a few films.