In Hoyt City, the dedication of a statue commemorating the city's founder, Ethan Hoyt, prompts reporters to converge on the home of one-hundred-year-old Hannah Sempler to urge her finally to reveal the secret of her association with Ethan. Hannah resents the scandal-mongers and sends them away, but softens her stance when a young biographer starts to leave in tears because, without information from Hannah, her biography of Ethan will be incomplete. Hannah recalls her past: In 1848, in Philadelphia, Hannah is smitten by young Ethan when he visits her father and asks him to invest in his plans for a city in an unpopulated area of the West. The shortsighted Sempler refuses, and although the spirited Hannah is engaged to stuffy Cadwallader, she runs away with Ethan and marries him on the trail to his Western property. Hannah adapts well to the difficult life of a homesteader and shares Ethan's dream of building a great city. When he gets drunk and loses their savings and property to gambler Steely Edwards, Hannah confronts Steely, a charmer who immediately falls in love with her, and wins everything back. Steely follows Hannah and Ethan for eight years as they move to California in search of gold. Hannah finally settles in Sacramento and runs a boarding house while Ethan continues to prospect. Ethan grows jealous of Steely, who is always with Hannah, although their relationship has remained platonic. One night Ethan returns from Virginia City feeling defeated because all he has found is some "blue stuff." Hannah tests deposits left on his boots and learns that they are silver. She borrows money from Steely so that Ethan can return to Virginia City and buy up the mines, but will not go with Ethan because she is pregnant. Hannah refuses to divulge her reason for not leaving for fear her pregnancy will keep Ethan from his dream, and Ethan, wrongly suspecting an affair between her and Steely, leaves her for good. Steely helps support Hannah, but when floods threaten Sacramento, he buys her and her twin babies a seat on a wagon headed for Virginia City, because he knows in his heart that Ethan will always come first for her. The wagon is washed off a bridge by a flash flood, and although Hannah survives, she loses the babies. Steely assumes that she has been killed and goes to Virginia City to give Ethan the news. Ethan, now rich, shoots Steely. Only wounded, Steely recovers and returns to Sacramento, where he finds Hannah, much changed because of the loss of her children. Hannah learns that Ethan has remarried and returned to Hoyt City, and decides to allow him to continue to assume that she is dead. By 1868, Hannah and Steely are operating a fashionable casino in San Francisco. Hannah leaves, however, after her father visits and is only concerned about the potential trouble her marriage may cause Ethan's campaign for Senator if anyone should discover she is alive. Hannah returns to Hoyt City and meets with the now corrupted Ethan, explaining what truly happened during the flood. Her visit rekindles the idealism that he has lost, and while she remains alone in their first home, Ethan realizes his dream of Hoyt City and goes on to become a great senator and civic leader. Hannah does not see Ethan again until 1906, when Ethan, who privately credits her with his achievements, returns home to die. His death coincides with Steely's death in the great San Francisco fire. Hannah's home on the original site of their cabin is now in the midst of a city, and she and the young biographer walk to the statue. The biographer, moved by the real story of how Hannah helped to make Ethan great, resolves to discard her biography so that she can fulfill her own destiny. Alone by the statue, Hannah rips up her tattered marriage certificate to ensure that no one will ever be able to taint the honorable memory of Ethan Hoyt.