The film opens with Scarlett O’Hara surrounded by admirers, but she is crushed when her father, Gerald O’Hara, tells her of Ashley Wilkes’s upcoming marriage to his cousin Melanie Hamilton. Scarlett’s father also reminds her of the importance and permanence of the land and their home, Tara, but she is too distraught to listen to him.
At a barbeque the next day at Twelve Oaks, the neighboring plantation, Scarlett is surrounded by even more admirers, but she is overtaken by jealousy when she sees Ashley and Melanie together. The roguish Rhett Butler sees Scarlett on the staircase and expresses interest in her, but Scarlett corners Ashley in the library to confess her love for him. When Ashley says they are too different to be together and leaves, Rhett reveals he has been listening the whole time.
The war quickly follows. Scarlett agrees to marry Charles Hamilton and holds the ceremony a day after Ashley and Melanie wed. Soon after, Scarlett receives a letter informing her of Charles’s death in the war. Scarlett travels to Atlanta to stay with Melanie and her aunt, and while there she meets Rhett again. Now a cynical war hero, Rhett pays $150 to dance with Scarlett at a charity ball. Those listening are shocked by the offer, but Scarlett seizes on his offer as her only chance to dance, since she is in her mourning period, and agrees. Afterward, Rhett visits her regularly.
The South begins to crumble as the war continues and deaths mount. Scarlett works as a volunteer nurse tending to wounded and dying soldiers. She still pines for Ashley, who during his leave makes Scarlett promise to look after Melanie. Atlanta is attacked by the Yankees, and in the resulting chaos Scarlett is forced to help deliver Melanie’s baby when the house slave, Prissy, backs down from the task. In the streets of the besieged city, Scarlett meets up with Big Sam, Tara’s former slave foreman, who tells Scarlett sketchy details of her family’s fate, including the news that her mother is ill. As the Confederates retreat, Rhett helps Scarlett, Melanie, the baby, and Prissy flee the city. Rhett leaves Scarlett, giving her his gun for protection, and he leaves to join the war effort. The women return to Tara to find Scarlett’s mother dead, her father helpless, and Tara in ruins. Undaunted, Scarlett ends the first part of the film resolving to do whatever she must to never go hungry again.
Part Two opens with Scarlett, her family, and the slaves picking cotton in the field. Later, when Scarlett discovers a Yankee deserter trying to loot Tara, she shoots and kills him with the gun Rhett gave her and takes the money he has stolen from others. Frank Kennedy asks Scarlett for the hand of Suellen, her sister, and Scarlett agrees to the match. Later, Scarlett discovers that the taxes on Tara have been raised to $300, an impossible amount. A despairing Scarlett once again meets Ashley in secret, declaring her love for him and asking that they run away together. Ashley replies that Scarlett could never leave because she loves the land too much.
When Tara’s former overseer returns and attempts to buy the property, Scarlett refuses. Her father mounts his horse to chase the overseer away but falls off during a jump and dies. Scarlett goes to Atlanta in an attempt to charm Rhett into paying her debt, but Rhett is a Union prisoner, jailed for blockade running and war profiteering. He realizes what she’s up to and tells her that his money is tied up in Europe. On the way back to Tara, Scarlett runs into Frank, whom she marries for the tax money after she lies that Suellen is engaged to someone else. Scarlett uses Frank’s money to build a successful mill and shames Ashley into working there. Later, Scarlett is attacked by hobos on her way through Shanty Town to the mill, and on a revenge mission Frank is killed and Ashley is injured. Rhett, who tried to stop the men from going, protects the remaining men from any repercussions that might result from their investigation of Yankee officers by claiming they spent the night in a brothel run by Belle Watling.
Rhett asks Scarlett to marry him, and she finally says yes. After moving to Atlanta they have a daughter they name Bonnie Blue, after an early Confederate flag. Scarlett says this will be their last child because she is still in love with Ashley. Rhett leaves, though Belle convinces him to return because Bonnie needs him. Rhett and Scarlett’s marital problems continue. Finally, after getting drunk one night, Rhett swears he will drive Ashley out of Scarlett’s mind forever and carries Scarlett upstairs to their bedroom.
The next morning Rhett leaves, taking Bonnie with him to London. When Bonnie says she wants to go home to her mother, Rhett returns her to Scarlett and then says he’s leaving again. Scarlett admits that she’s pregnant and that she doesn’t want the baby. Rhett says cynically that maybe she’ll have an accident. Immediately, Scarlett falls down the stairs and loses the baby. Some time later, Rhett and Scarlett are sitting on their porch, discussing the possibility of a reconciliation and watching Bonnie ride her pony. Bonnie attempts a jump and dies when she fails to clear the fence. Rhett goes mad with grief and, despite the pleas of Mammy, an old slave, temporarily refuses to allow his daughter to be buried.
These events prove to be too much for Melanie, who is already weakened by fatigue and a second pregnancy. She collapses. Before dying, she asks Scarlett to look after Ashley and their child, Beau, and to be kind to Rhett. When Scarlett sees how stricken Ashley is, she realizes that she and Ashley will never be together and rushes home to tell Rhett that it’s him she really loves. When she arrives, though, she finds Rhett leaving for good this time, preparing to return to Charleston. Scarlett begs him not to go and asks what she will do without him, to which Rhett replies, “Frankly, my dear, I don’t give a damn.” Scarlett decides to go to Tara to think of a way to get him back, reminding herself that “tomorrow is another day.”