In Chattanooga, Tennessee, railroad magnate Alonzo Dillard celebrates his birthday. Meanwhile, Alonzo’s conniving son-in-law, Bert Waters, who owns the Chattanooga Choo Choos football team, is with his mistress, Maggie Jones. He promises that he will marry her once he divorces his wife, Estelle Dillard Waters. Sometime later, at Alonzo’s party, Bert shows his daughter, Jenny, doctored photos of her fiancé, Paul, with other women, provoking Jenny to end the engagement. Bert then attempts to steer his daughter’s affections to Mason Forsythe, the Duke of Chalfont. Soon after the birthday party, Alonzo dies and is buried in a boxcar. At the funeral, Bert declares he will prevent Paul’s father, Sam Cartwright, from winning the bid to build a new football stadium. Two months later, Alonzo’s attorney reads his will, which bequeaths his former porter, Woodrow Lynton, $100,000, and a salary for life. Alonzo leaves his granddaughter, Jenny, $5 million and his daughter, Estelle, the remainder of his estate. To Bert, he issues a challenge. Referring to the lyrics of the popular song, “Chattanooga Choo Choo,” Alonzo states that Bert will receive $1 million if he can restore Alonzo’s beloved train, the Chattanooga Choo Choo, and run it from New York City to Tennesse in twenty-four hours. After the reading, Mason announces that he and Jenny are engaged. Later, two bikers confront Bert and mock his lavender Cadillac, but Bert instructs his driver and bodyguard, Hashimoto, to destroy their motorcycle. Bert then shares the news of his potential windfall with his mistress Maggie, but she questions why his divorce has not yet been finalized. When he says he must wait until Estelle is out of mourning, Maggie misinterprets Bert’s plans for Jenny’s wedding as an arrangement of their own nupitals. After being out of commission for thirty years, the Chattanooga Choo Choo is restored. On the day of departure, Bert introduces his football team and their coach, Orville “Newt” Newton, to the media. The team’s players, cheerleaders, and marching band, board the train, along with an official from the city. Bert attempts to bar his nemeses, Sam Cartwright and Paul Cartwright, but they already purchased tickets. On the platform, Estelle telephones a caterer to make arrangements for Jenny’s marriage. Maggie nearly misses the train when she drops her suitcase on the platform, but Newt helps her aboard. The train leaves the station on track twenty-nine at a quarter to four as prescribed by the song, leaving Estelle behind. On board the train, Maggie meets Jenny and Mason, and thinks she remembers the duke from high school. He assures her he attended school in England. When Woodrow, the porter, informs Bert they are eleven minutes behind schedule, Bert instructs him to bypass an optional stop in Philadelphia, Pennsylvania. Meanwhile, Estelle takes a taxicab to Philadelphia to meet them. In the dining car of the train, Paul asks Jenny why she broke up with him and is befuddled when she replies, “twins,” alluding to Terri and Susie, a pair of sisters on the cheerleading squad. Maggie buys Newt a drink to reward him for his earlier kindness, and Bert is surprised to see her on the train. Still confusing Jenny and Mason’s wedding for her own, she says she is onboard for their marriage ceremony. Bert informs her that the wedding is the next day in Chattanooga and invites her to his private car, prompting Newt to suspect an affair. Later, Bert receives Sam’s stadium bid from the city official. So, Sam plans to get off the train in Philadelphia, fly back to Chattanooga, and re-submit the bid. Meanwhile, the train bypasses Estelle in Philadelphia, and Sam is forced to disembark in Washington, D.C. Meanwhile, one of the football players, Jim Bob, slips a laxative into Bert’s soup. It begins to take effect and Bert is forced to wear a woman’s skirt. He orders Hashimoto to prevent Sam from leaving the train. Maggie confides to Newt that she is marrying Bert the next day. When the train stops in Washington, Bert recites a speech, Hashimoto renders Sam unconscious, and Estelle finally makes it aboard. Bert hustles Maggie out of sight, and she realizes that he is still not divorced. She takes refuge in Jim Bob’s room and discovers he has a peephole into the cheerleader’s quarters. The next morning, in the dining car, Jenny confronts Terri and Susie, the girls in her father’s doctored photographs, but they have never met Paul. Maggie asks Mason if he ever played piano at a club in Mobile, Alabama, and the duke is insulted. Maggie shows the cheerleaders Jim Bob’s peephole and they conspire to glue his eyebrow to the wall. Later, Maggie discovers Sam Cartwright unconscious in the baggage car and is confronted by Hashimoto, but she escapes to alert Sam’s son, Paul. They convince Hashimoto to abandon his post by claiming that kidnapping is a federal offense. Newt reluctantly agrees to impersonate Sam in the baggage car by hiding under a blanket, while Lyle, a friend of the Cartwrights, lands a single-seat, “Ultra Lite” aircraft on top of the train. Sam escapes in the plane after instructing Paul to stay and win back Jenny. In the baggage car, Bert tells Maggie that she is too friendly with Newt, and insists the coach is not good enough for her. Overhearing his boss defame him, Newt leaps up to defend himself, and Bert realizes Sam is gone. Meanwhile, Estelle enters the baggage car and is upset to see Maggie; she reveals she knows about Maggie’s affair with Bert. When Maggie informs her the affair is over, Estelle leaves and Bert follows. Alone, Maggie and Newt confirm their feelings for one another. In the corridor, they run into Mason, and Maggie finally remembers how she knows him. His real name is “Bob Shoemaker” and he is a numbers runner from Memphis, Tennessee. Although Mason attempts to run away, Newt tackles him. The duke denies the accusation, but the football team dangles him out the train window of the train until he admits his deception. The team places him in a mailbag and leaves him at the next station. Later, Newt convinces Jenny to reconcile with Paul. As the train approaches Chattanooga, Bert announces they are slightly ahead of schedule and toasts the deceased Alonzo Dillard with champagne. However, the train comes to a sudden halt when the two bikers park Bert’s stolen Cadillac on the railroad tracks. Hashimoto and the football players brawl with the bikers as Bert moves his car. The delay causes the train to arrive in Chattanooga two minutes late, nullifying Bert’s million-dollar inheritance. As the passengers disembark, Maggie and Newt bid farewell to Bert, and Jenny and Paul inform him of Mason’s true identity, and that they will be the ones getting married. Although Sam won the building rights to the new football stadium, he will give Bert a fair deal to allow his team to play there. Estelle tells Bert that they will speak to divorce lawyers after their daughter’s wedding, and Hashimoto and Woodrow refuse to take any more orders. Later, the minister reluctantly marries Jenny and Paul, and Maggie and Newt, simultaneously. The newlyweds depart for their honeymoon on the Chattanooga Choo Choo. A dejected Bert finds solace when one of the cheerleaders, Mary Lou, admires his Cadillac, and he offers her ride.