Trivia: If you look closely, there are many "Mickeys" in the scenery. For example, look in the bushes in various scenes and you will see three circles that form Mickey's head.
Trivia: The initial premise of the movie, that the nearly-new U.S.S. Sea Tiger was sunk pierside at Cavite on 10 December 1941, then hastily repaired, is based on fact. A nearly-new American submarine was indeed sunk pierside at Cavite on 10 December 1941. Unfortunately, the real-life submarine could not be repaired in time, and had to be blown up. Her name was U.S.S. Sea Lion (SS-195).
Trivia: The dimitrodon, the dinosaur in the middle of the movie, is actually a real lizard (a basilisk, in fact) with a sail glued onto its back.
Trivia: This movie is based (loosely of course) on an actual Civil War raid led by Colonel Benjamin Grierson. See: "Grierson's Raid: A Cavalry Adventure of the Civil War" by Dee Brown.
Trivia: In the cartoon's opening title credits, there is no "Layout" next to Robert Gribbroek's name, which makes him appear to be an animator.
Trivia: When Moira and Bill Davidson are strolling in the pasture, they pause to admire a beautiful mare that is posing for them, and Bill offers the horse something to eat from the palm of his hand (sugar cubes or some other treat, presumably, but it's not visible). However, the horse does not react to the treat nor eat anything that Bill offers, because the actor's hand was actually empty. The trained horse was obeying cues from her trainer, off-camera, and only her trainer carried the real treats.