Gulliver's Travels was the second feature-length animated film ever, and this quickly-fading novelty is the only sensible reason it made any money at all in 1939—because the most useful thing it ever does otherwise is provide a handy 86 minute explanation of why feature animation effectively stayed a Disney monopoly for half a century afterwards.
1939
Directed by Dave Fleischer
Written by Dan Gordon, Cal Howard, Tedd Pierce, Edmond Seward and Isadore Sparber (based on Travels into Several Remote Nations of the World. In Four Parts. By Lemuel Gulliver, First a Surgeon, Then a Captain of Several Ships by Jonathan Swift)
With Sam Parker (Lemuel Gulliver), Pinto Corvig (Gabby), Jack Mercer (King Little III), Tedd Pierce (King Bombo), Jessica Dragonette and Livonia Warren (Princess Glory), and Lanny Ross and Cal Howard (Prince David)
Spoiler alert: hell, it only gets one fourth of the way through