Seeing how miserable her eldest daughter is, her mother allows Scarlett to go to Atlanta, Georgia to stay with Melanie, although Scarlett really has Ashley in mind. While there, she sees Rhett Butler (Clark Gable), with whom she had the brief encounter with at the party. Rhett has become a privateer, smuggling goods to the south past the northern naval blockade. He makes Scarlett very uncomfortable, especially after Melanie offers her wedding ring to raise money for the army and Scarlett gives hers as well. Rhett respects Melanie deeply, but knows that Scarlett's offer of her wedding ring means nothing at all to her. But bored at wearing interminable black mourning clothes and being prevented from dancing, which she loves, she agrees to dance with him when he offers a large donation for "The Cause" for a dance with her, something which her elders think she should not do since her husband had just died and she is in mourning. But when Melanie thinks it would be all right because she would only be doing this for the donation, Scarlett dances with Rhett to the Virginia Reel.
A few months later, the battle gets close to Atlanta, and as rumors of the Union Army invading Atlanta increase, Melanie's Aunt Pittypat, a neurotic hysteric, leaves the two young women alone. Scarlett goes to Melanie to tell her they ought to get out of the city as well, only to find her sister-in-law in labor with Ashley's baby, conceived on his last, brief leave. The doctor is too busy trying to care for the thousands of wounded Confederate soldiers, so with only Scarlett's inexpert help, Melanie gives birth to a boy. Thinking she may die, Melanie asks Scarlett if she would take care of her son. Scarlett, already terrified but not wanting Melanie to see, tells her not to be such a silly goose and sends her maid Prissy to find Rhett. He's playing cards in a brothel, and Prissy stands outside, calling his name, afraid to enter. When he finally comes to the window, she tells him that Miss Melly had her baby (although she takes the credit for most of it, saying Miss Scarlett "helped a little") and Miss Scarlett wants Rhett to come because the Yankees are coming. After a loud explosion sends Prissy into hysterics, Rhett finds one of the last remaining horses in Atlanta, and a wagon for it to pull. Scarlett begs Rhett to take them home to Tara, finally sobbing that she wants her mother. That softens Rhett's heart, as does the sight of Melanie, who can barely hold onto him as he lifts her from her bed, and at her nearly inaudible request, translated by Scarlett, takes along her most prized possessions: one possession each of her husband's and brother's. After loading the wagon, placing Melanie, in great pain from the difficult birth, with her baby in the wagon bed, he manages to laugh at Scarlett because she's concerned that she forgot to lock the front door.
Rhett tries to outrun both the retreating Confederate Army, who want the horse, and the approaching Union Army. They race against the background of the great fire caused by the Confederate Army destroying the fuel depot to prevent it from falling into the enemy's hands. However, after escaping Atlanta, Rhett stops the wagon under a bridge over which the Confederate soldiers are marching. It is pouring rain, and the very weak and ill Melanie tries to protect her infant from the weather. Rhett informs Scarlett that he is leaving to join the army. She argues with him, but he won't be swayed, and when he asks for a kiss for a departing soldier (meaning himself), Scarlett slaps him instead, declaring her eternal hatred for him. The three women finally reach Twelve Oaks, the Wilkes' family home, burned to the ground. This sight makes Scarlett even more determined to get to Tara and her mother, and she whips the poor tired horse in a frenzy. The horse collapses and dies. They find Tara in very bad shape; her mother has died and her father's mental state seems unstable. Scarlett famously vows to always take care of herself and her family, no matter what it takes, because she nor her own will ever be hungry again.
After an intermission (a short break used in very long movies), the movie returns to Tara, where Scarlett and her family are working very hard to survive. The far-away war is over now, and despite Scarlett's protests, they share their food with returning Confederate soldiers passing through. Ashley Wilkes returns, recognized from far away by Melanie, who runs to greet her husband. When Scarlett realizes who it is, she too starts to move towards him, held back by Mammy's reminder that he's Melanie's husband. They continue to work the land themselves, without the assistance of the slaves such a plantation required. Tara's previous overseer, fired by Scarlett's mother for what she considered his unacceptable behavior with the local trollop, has become a powerful man in the county, and out of revenge, raises their taxes beyond what they can afford to pay. Scarlett finds out that Rhett Butler is in jail and she plans to trick him into giving her some money to help her family. However, the scheme does not go according to Scarlett's plan, and after leaving Rhett's jail, Scarlett meets Frank Kennedy, her sister Suellen's intended husband. Realizing that he has a good business, which she intends to improve and save Tara, Scarlett decides to marry him, despite the fact that he was going to marry her own sister.
Scarlett is assaulted in her carriage while driving along the road. She is not harmed, because one of the former field slaves from Tara is living in a shantytown and rescues her, after which she tells him to go home to Tara. But Frank and the other men decide to go clear out the shantytown, where former slaves and criminals lived after the war because they had no homes to return to and no way to feed themselves. During this act, illegal under the laws imposed by the occupying Union Army, Frank, is killed and Ashley wounded. Rhett, known to be friends with many of the Northern soldiers, uses his quick wits and concocts a plan with Melanie, who trusts him, and the other women, who trust Melanie's judgment. Soon after, Scarlett again shocks the "Old Guard", i.e. the remaining southern Atlanta families of her class, by accepting Rhett Butler's proposal. They enjoy their honeymoon in New Orleans, including Scarlett's obvious enjoyment of the vast amounts of delicious foods and the closeness between them at night when he soothes her as she is awakened by a repeated nightmare. Rhett promises to help rebuild Tara and they build another mansion in Atlanta. Enjoying her riches and security for the first time since the war began, Scarlett becomes increasingly greedy, furnishing her new mansion opulently and in Rhett's opinion tastelessly. She holds parties inviting northern carpetbaggers, while the southerners of her acquaintance remain poor and dressed in rags. But Melanie, one of the most respected of all the women of Atlanta, makes it clear that Scarlett and Rhett are still to be accepted in her world.