Rodeo star Roy Rogers returns home to find that his old friend Tom Craig has been murdered after he was accused of stealing a family crest from Helen Williams. Helen joins up with Roy and Gabby Whittaker to find the killers and the crest.
A young outlaw gets involved with a gang of crooks. When he tells them he is breaking away, they threaten to pin a false murder charge on him. But he is rescued and reformed by his sister, and an undercover agent for the express company.
During World War II, a young boy and girl, living with their respective families in an apartment house that had restrictions against pets, adopt a lost dog and hide it in a vacant apartment, which may have been the only vacant apartment in the United States at the time this movie was being filmed. A burglar breaks in and the apartment is damaged when the dog and crook have a tussle. This blows the dog's cover, but the kids enlist him in the K-9 Corps, and the dog distinguishes himself in the WWII Italian campaign
Cutthroat pirate William Kidd captures Admiral Blayne's treasure ship and hides the bounty in a cave. Three years later, Kidd, posing as a respectable merchant captain, offers his services to the King of England. Seeking a social position, Kidd also negotiates for Blayne's title and lands, provided he can prove Blayne was associated with piracy. Launched upon his royal mission, Kidd is unaware that Blayne's son Adam is among the crew, determined to clear his father's name.
The Trail Blazers are bringing in a prisoner to stand trial for bank robbery, when several attempts are made to kill him; convinced of the man's innocence, they arrange a trap for the real thieves.
A naval officer who had deserted several years earlier is drawn back to the Navy when World War II begins. He re-enlists under an assumed name, and is assigned to a minesweeper, where he has to perform hazardous duties while at the same time keeping his real identity a secret.
A man of no worth brags to his daughter back East that he is rich and owns a big ranch. When she decides to pay a visit to her father, Roy and his buddies agree to pretend that the poor man is the owner of the ranch.
Judge Kirby is being blackmailed and forced to let outlaws go free. He was once the partner of Roy's father and when Roy reads in the paper that he is in trouble he heads out to help him. Arriving, Roy quickly realizes he has been mistaken for one of the outlaws and is not wanted in town. However he stays, and now posing as that outlaw, hopes to learn who is causing all the problems.
A Nazi spy ring is after a chemical formula that increases the power of ordinary gasoline for U.S. Army aviation use. Two U.S. chemical companies are developing the formula, with each working on half for security purposes. The spies get half the formula and know that either of two chemists, Robert Norton or Tom Fielding, knows the rest. They capture Fielding, through a ruse by gang member Linda Pavlo, and threaten the life of his sister Nancy and his mother if he does not give them the formula. To protect his friend Fielding, who does know the formula and is engaged to Nancy, Tom pretends to know the secret and boards the Dawn Express plane with the spy leader and his gang.
The Mesquiteers return to Texas after the Civil War to find Army carpetbaggers fighting the local bushwackers. They quickly learn that Capt. Hawks and his men are the culprits and join up with Morgan and his men.
The mayor has sent for a gunslinger who, though appearing to clean up the town, is really to be the mayor's means of taking the town over. When Roy and Gabby arrive in Tombstone, Roy is mistaken for the gunslinger. Just as Roy is ready to expose the mayor, the real gunslinger shows up.
A group of young men who work at an aviation factory begin to suspect that a doctor who runs an air ambulance service is secretly a spy transporting secret information from the plant to enemy agents.
When the showboat hits town, two men use the parade as a distraction to rob the bank. Their accomplice is Pop, the clown from the showboat. He leaves the money on the boat and tells his daughter Patsy to bring it to him at a later stop on the river. Gene's investigation of a bank robbery takes him to the showboat where he becomes a performer. Gene and Frog try to find the money while helping Patsy and her father.
Muggs is tricked into entering a Civilian Conservation Corps camp by Danny in order to get in shape. Muggs resists and battles with the camp captain and with other campers. He also becomes involved in trying to help one of his friends get out of trouble.
Bill Hickok, assisted by Calamity Jane, is after a foreign agent and his guerrilla band who are trying to take over some western territory just as the Civil War is coming to a close.
While Sam Houston in in the nation's capital trying to get Texas into the Union, his aide is trying to impose a self-serving tax on the use of the Santa Fe trail. The lady owner of a wagon train is using the trail, and a Texas Ranger comes to her assistance.
Gulliver washes ashore on Lilliput and attempts to prevent war between that tiny kingdom and its equally-miniscule rival, Blefiscu, as well as smooth the way for the romance between the Princess and Prince of the opposing lands. In this he is alternately aided and hampered by the Lilliputian town crier and general fussbudget, Gabby. A life-threatening situation develops when the bumbling trio of Blefiscu spies, Sneak, Snoop, and Snitch, manage to steal Gulliver's pistol.
Ann Fenwick is a witness to a bank robbery in the U.S. and the bandits, led by Trigger and Leon capture her and when she disappears, a warrant is issued for her arrest as a material witness. The bank robbers flee across the border into Canada where they steal a trailer in which they lock Ann and the loot. The hitch breaks and the trailer plunges into a lake. Sergeant Renfrew and Constable Kelly, of the Canadian Mounties, rescue Ann and she tells them she is a hitch-hiking tourist and gives a false name. Renfrew sends Kelly for aid, Ann escapes and Kelly returns with the news that she is wanted. The leader of the gang, Cardigan, sends the gang back for Ann and the loot, which Ann has hidden in a trappers cabin, just before Trigger recaptures her. Renfrew goes to her rescue, but is also captured. But reliable Constable Kelly is somewhere in the woods.