Scene 1. The levee at Natchez on the Mississippi, late 1880s
A show boat, the Cotton Blossom, is in town. When the boat’s cook, Queenie, arrives from the market, Pete, the engineer, demands to know who gave her the brooch she’s wearing, but she responds evasively. Stevedores and townsfolk assert that workers get no rest because of the show boat. Steve Baker, the boat’s leading actor, has placed near the gangplank a picture frame showing his wife, leading lady Julie La Verne. Pete steals the picture and stealthily heads for the towboat. A crowd gathers to hear Captain Andy Hawks’s description of the evening’s show. Pete is furious that Julie gave his gift to her—the brooch—to Queenie. Seeing Pete pestering Julie, Steve exchanges blows with Pete, who is then fired by Captain Andy. Parthy, Andy’s wife, despises show people and warns Julie to have nothing to do with her daughter, Magnolia. Ellie May Chipley, the company’s comedienne, fails to persuade Andy to give her dramatic roles if Julie leaves the company.
A dashing gambler, Gaylord Ravenal, appears on the levee. He tells Sheriff Vallon he’s there for a short time, but Vallon warns him not to stay more than 24 hours. Suddenly Ravenal sees Magnolia and is instantly captivated. WhenVallon announces that the judge would like to see Ravenal, he excuses himself politely. Magnolia asks Joe, a worker on the show boat, whether he knows the young man she was talking to. He doesn’t, but he’s seen his kind before on the river. She rushes off to find Julie. Joe believes the river will know—it knows everything.
Scene 2. The show boat’s kitchen
Magnolia tells Julie she’s in love, although she doesn’t know the young man’s name. Julie worries that he’s a “no-account river feller.” If he were, answers Magnolia, she’d stop loving him, but Julie knows otherwise and sings a song expressing her feelings. Queenie—surprised that Julie knows the song—adds her own exasperated verse about Joe.
Scene 3. Outside a waterfront saloon
Ravenal declares that if he loses at gambling today, he knows that things will go better for him later.
Scene 4. The show boat’s stage
Queenie and the boat’s workers sing a song about keeping unhappiness far away. Julie begins singing it herself, but as everyone joins with her, she suddenly cries out, “Stop singing that rotten song!” She manages to rehearse with Andy, Steve, and the company’s resident villain, Frank Schultz.
Ellie, arriving late, whispers something in Steve’s ear. When he whispers it to Julie, she collapses. Knowing the sheriff is on his way, Steve pulls out a knife, cuts Julie’s finger, and sucks blood from it. Vallon arrives, informing Andy that in Mississippi it is unlawful for a Negro woman to marry a white man. In this case, he accuses Julie (whose last name he identifies as “Dozier”) and Steve, who defiantly responds that he has Negro blood in him. Vallon advises that Andy cancel that evening’s performance and departs. To Magnolia’s dismay, Steve and Julie—intending to leave the company—go off to pack.
Andy does plan to cancel the performance, but wonders about tomorrow. He decides to assign Julie’s role to Magnolia, who knows all the lines. To play opposite her, Frank suggests a gentleman he just met. He brings in Ravenal, who is immediately hired. Julie says goodbye to Magnolia, who sadly begins rehearsing with the enraptured Ravenal.
Scene 5. In front of the show boat’s box office
Ellie sings to the Natchez girls about the sacrifices one makes in being an actress. Queenie goes into a vigorous sales pitch for the show.
Scene 6. Stage of the show boat
A melodrama is performed, with the embrace between “Parson Brown” (Ravenal) and “Miss Lucy” (Magnolia) drawing enthusiastic applause. When Frank, as the villain, grabs Magnolia, a patron shoots his gun in outrage!
Scene 7. The show boat’s upper deck
Knowing Parthy will be preoccupied and unable to interfere, Ravenal convinces Magnolia to marry him the next day. The two are ecstatic.
Scene 8. The levee
The public is invited to the wedding. Magnolia and Ravenal are headed for a Natchez church when Parthy rushes in with Vallon and Pete. Everyone is shocked when Parthy accuses Ravenal of having killed a man the year before. Vallon admits that Ravenal got off on self-defense, at which Andy expresses no objection, admitting that when he was nineteen he, too, killed a man. Hearing that Magnolia and Ravenal are going to marry, Parthy faints. Andy declares that the wedding can now proceed.
Scene 1. Chicago World’s Fair, 1893
Ravenal and Magnolia make merry with Chicagoans, dazzled by the Columbian Exposition. Feeling that luck is with him, Ravenal goes off to gamble.
Scene 2. A suite at the Palmer House, Chicago
Life feels blissful for Magnolia and Ravenal.
Scene 3. The show boat
Andy reads Parthy their daughter’s letter describing her life with Ravenal. Parthy disapproves of how much they are spending on luxuries. Andy proposes a trip to Chicago to see the Ravenals and Kim, their daughter.
Scene 4. A room on Ontario Street, Chicago, 1904
At a boarding house, Frank and Ellie ask the landlady about renting a room. Incensed that her current occupants haven’t paid their rent in weeks, Mrs. O’Brien is planning to get rid of them. She reveals, too, that the man is a gambler and that everything he and his wife own has been pawned. Frank and Ellie are astonished when Magnolia arrives. She explains that these are temporary quarters, prior to her moving with Ravenal to the lake shore. Sensing that Magnolia needs money, Frank offers to get her a job singing. Mrs. O’Brien hands Magnolia a letter from Ravenal, enclosing money for Kim’s school expenses. With nothing left to pawn and no more friends to lend them money, Ravenal is leaving Magnolia, hoping she and Kim will return to Andy and Parthy. Magnolia tells Frank and Ellie she refuses to live on charity while enduring her mother’s disapproval.
Scene 5. St. Agatha’s Convent, Chicago
Ravenal explains to Kim that he must soon leave for “a business trip.” Kim tells her father that when she misses him, she does what he always told her to do—she pretends that they’re together.
Scene 6. The Trocadero Club
Jake, the pianist, tells Max, the owner, that Julie, their singer, is having a tough time: Steve has just left her, saying he couldn’t compete with the other man in her life - “Johnnie Walker.” When Julie appears, Max threatens that if she misses the evening’s show, she’ll be out of a job. She rehearses a new song.
Frank, recently hired with Ellie as the Trocadero’s comedy act, asks Max to audition Magnolia. Seeing how lovely she is, he consents. She sings the song she’d heard Julie sing years before. Julie is startled to hear her voice and then to see her, although Magnolia has no idea her old friend is there. Having made her decision, Julie leaves.
Magnolia’s singing pleases Max, but he upsets her by saying he dislikes the song. The maître d’ appears with a message from Julie—she’s “going on a tear.” Max fires her, but there’s more to the message: Julie suggests he hire the girl who just auditioned. Frank encourages Magnolia to try her song at a livelier tempo, and when she does so, Max gives her the job.
Scene 7. Lobby of the Palmer House
Having arrived in time for New Year’s Eve, Parthy and Andy can’t locate the Ravenals, who they thought were staying at the Palmer House. Parthy goes off in search of them, while Andy flirts with some attractive ladies.
Scene 8. The Trocadero Club, New Year’s Eve
The club’s orchestra and dancers perform followed by Ellie and Frank. Astonished to see Andy, Frank tells him that Ravenal has left Magnolia, who is now performing at the club. Max informs the audience that “Julie Wendell” will be replaced by Magnolia Ravena[, who quietly begins a sweetly sentimental waltz song. Seeing Andy in the audience increases her confidence, and by the end the crowd is singing along with her. She embraces her father as everyone shouts, “Happy New Year!”
Scene 9. In front of The Natchez Evening Democrat
Joe reflects on the never-changing Mississippi River.
Scene 10. A Broadway theater
An emcee introduces Magnolia, now a great star. She sings two songs for the Ziegfeld Follies audience.
Scene 11. Outside the show boat
Ravenal meets Andy, who informs him of Magnolia’s European successes and that she is, in fact, on the show boat this very evening. Ravenal sadly recalls his love for Magnolia.
Scene 12. Levee at Greenville, 1927
After forty years together on the show boat, Queenie remains as frustrated as ever with Joe. When a woman compliments her on her dress, she reveals that it was a present from a Broadway star, Miss Ravenal. She delights the Greenville crowd with a song from Kim’s latest show.
As the audience leaves following the show boat’s evening performance, Magnolia sees Ravenal. He is about to beg forgiveness when an old lady, recognizing Magnolia, interrupts. She remembers Magnolia’s debut performance, the handsome young man who looked at her with such feeling, and the loving way she gazed at him. “And to think, it was only make believe,” murmurs the lady, bidding Magnolia good night.
Ravenal is again begging forgiveness when Magnolia sees Kim, who rushes to embrace her father. For one moment the family is united, as Joe’s voice is heard once again.