In St. Louis, in the summer of 1903, seventeen-year-old Esther Smith fantasizes about meeting John Truett, the shy boy-next-door, while her older sister Rose frets about her beau, Warren Sheffield, who is off at Yale. Sure that Warren, who is calling Rose at 6:30 that evening, is finally going to propose to her sister, Esther arranges with Katie, the Smiths's housekeeper, for the family to eat dinner early, so that Rose will have some privacy while talking on the telephone. Esther's cantankerous father Alonzo, who has not been told about the expected call, ruins her plan, however, when he insists on eating at the usual time. During dinner, everyone, including Esther's five-year old sister "Tootie," tries to hurry Lon along, but the phone rings just as the main course is being served. As her family eavesdrops on the entire conversation, Rose attempts to prod Warren into a proposal, but he gets mired in small talk and hangs up without uttering a single romantic word. Later, at Esther's urging, Rose invites John to a farewell party for her older brother Lon, Jr., who is going to Princeton. At the party, Esther at first feigns indifference to John, but hides his hat to keep him at the house and then asks him to help her turn off all the lights. Although John is clearly attracted to the flirtatious Esther, he is too shy to kiss her, and instead gives her a hearty handshake. Before he leaves, Esther invites him to join her family that Sunday for a tour of the St. Louis Exposition fairgrounds, and he tentatively accepts. On Sunday, Esther waits eagerly for John at the trolley stop, but he has not arrived by the time the trolley is scheduled to leave. As the trolley is pulling away, however, John appears and, to Esther's joy, hops on next to her. Months later, Tootie and her slightly older sister Agnes dress up as goblins and go out to celebrate Halloween with the neighborhood children. Anxious to prove herself, Tootie, who is preoccupied with death, insists on calling feared neighbor Mr. Braukoff to his door and, following the local custom, blows flour in his face. After Tootie is declared the "most horrible," she throws her family into a panic when she returns home, crying, bruised and cut. Tootie claims that John hit her by the trolley tracks, and although Esther at first refuses to believe her, she changes her mind when a clump of hair is discovered in Tootie's hand. Enraged, Esther storms over to John's house, accuses him of being a bully and then beats and bites him. Later, however, Tootie and Agnes confess that John actually saved them from being arrested after they almost caused an accident on the trolley tracks. Esther rushes back to John's house to apologize, and John not only forgives her, but flirts with her as well. Later that evening, Lon, a lawyer, returns home to announce that his firm is transferring him to New York. Although Lon is enthusiastic about the transfer, which involves a promotion, Anna and the children react with shock and worry. Eventually, however, Anna agrees to the move, and the Smiths plan to leave St. Louis after Christmas. Weeks later, on Christmas Eve, Rose is upset because the visiting Warren has invited Lucille Ballard, an Easterner, to the local Christmas dance instead of her. Back from Princeton, Lon, Jr., also is frustrated because he wanted to ask Lucille to the dance. After Katie convinces Lon, Jr., to escort Rose to the dance, Esther's plans are disrupted when John is forced to break his date with her because he did not get to the tailor's soon enough to pick up his tuxedo. Although Esther assures John she is not upset, she later breaks down in tears and refuses to be escorted by Lon, Jr. When Esther's grandfather, however, offers to take her, she gratefully accepts. At the dance, Esther and Rose scheme against Lucille, whom they have never met, by filling out her dance card with the names of clods. Their plan backfires when Lucille turns out to be nice and insists that Rose be with Warren, while she goes with Lon, Jr. Embarrassed, Esther gives Lucille her dance card, then braves the clods. To her delight, John eventually shows up and, under a wintery moon, kisses her and proposes. As soon as Esther starts to think about being separated from her family, however, she has second thoughts about marrying. Later, at home, Tootie cries to Esther about the impending move and, as her bewildered father watches from a window, runs outside and angrily begins smashing the snow people she helped build. After calling the family together, Lon then announces that that they are staying in St. Louis. Months later, the Smiths and John head for the just-opened Exposition and are thrilled by the thought that such incredible sights are in their very own town.