Posing as a hangman, Mace Bishop arrives in town with the intention of freeing a gang of outlaws, including his brother, from the gallows. Mace urges his younger brother to give up crime. The sheriff chases the brothers to Mexico. They join forces, however, against a group of Mexican bandits.
The Elder boys return to Clearwater, Texas for their Mother's funeral. John the eldest is a well known gunfighter and trouble follows him wherever he goes. The boys try to get back their ranch from the towns gunsmith who won it from their father in a card game with which he was shortly murdered there after but not before getting through the troubles that come with the Elders name. The four sons of Katie Elder reunite in their Hometown of Clearwater, Texas for their Mother's funeral, and discover that the family ranch is now in the hands of Morgan Hastings, the town's gunsmith.
A cross-country road race is based on an actual event, the Cannonball Baker Sea to Shining Sea Memorial Trophy Dash, organized by Brock Yates to protest the 55 mph speed limit then in effect in the U.S. The Cannonball was named for Erwin G. "Cannonball" Baker, who in the roaring 20's rode his motorcycle across the country. Many of the characters are based on ruses developed by real Cannonball racers over the several years that the event was run.
The original characters from the first Cannonball Run movie compete in an illegal race across the country once more in various cars and trucks.