After a bout with polio, future president Franklin Roosevelt fights to save his political career.

In the summer of 1921, Franklin Delano Roosevelt spends carefree months at his summer home on Campobello Island in New Brunswick, Canada with his wife Eleanor and their five precocious children. While enjoying the sunset on 10 August, he loses strength in his legs and falls. By sunrise, he has fallen again and a specialist later diagnoses the problem as infantile paralysis or poliomyelitis. Word of Franklin's debility brings to the island his close friend and shrewd advisor, Louis McHenry Howe, who has an almost mystical belief that Franklin's political career is "ordained." A couple weeks later, Franklin's mother, Sara Delano, an overbearing widow who finds the asthmatic Louie's dry humor and unpretentious conversation vulgar, arrives from overseas. Louie is a source of comfort and stability for Eleanor, who has been Franklin's only nurse on the understaffed island, and he is able to assure the oldest son, James, of his father's ability to win tough battles. However, with the domineering Sara, who obviously dislikes him, Louie can manage only the civilities and refuses to discourage Franklin from public service and "grandiose schemes," as she wishes. Franklin, despite his secret despair, continues to plan for a busy future and Louie orders Franklin's secretary, Missy Le Hand, to believe in him. At the end of the summer, the time when the family usually returns to New York, Franklin is still bedridden and the press is staking out the area, clamoring to see evidence of his weakened condition. To protect Franklin's reputation, Louie arranges for his departing family to serve as a decoy to lure the press away from Franklin, who is transported separately by stretcher to a different ferry. Afterward, Louie releases a confident announcement about Franklin's expected recovery, while Franklin is hospitalized for several months. After returning to his home in New York City, Franklin is fitted into leg braces, puts wheels on a chair and invents other gadgets to help him go about his daily tasks, in the belief that he will someday completely recover. With the help of Missy and Louie, Franklin maintains a public presence through correspondence, providing support for Woodrow Wilson's efforts toward world peace. Although he keeps actively engaged in the affairs of the world, he confides to Eleanor that he feels lonely and has nightmares about being trapped in a fire. To her surprise, he explains that he is teaching himself to crawl. Perceiving "fire" as a symbol of his trials, he believes that there is a reason he must endure them and that by having "to crawl before he can walk" again, he is learning humility. Hoping the news will lift his spirits, Louie reports that the New York Democratic Party is considering him for candidacy for governor, and Louie coaches Eleanor to be Franklin's "eyes, ears and legs" in the world by delivering speeches that he writes. Meanwhile, Franklin continues to pursue his many private interests, such as the Boy Scouts and the possibility of implementing air travel by dirigible. Claiming that the doctors have ordered Franklin to cut back on his activities, Louie urges Franklin to drop some of his organizations and interests in order to focus on upcoming Congressional elections, telling him that he should "let the people know" through his writing that he is a man of opinions and convictions. When Franklin crawls up the stairs to take a nap, Eleanor sees it as a small triumph of personal independence, but Sara is concerned about appearances. After Sara insists on trying to force her will on Franklin, Eleanor goes off alone to cry. Although Louie reassures her that she deserves a good cry, Eleanor announces that she "will never do that again." In July 1923, the family is summering at Hyde Park, where Franklin, much recovered but still unable to walk, roughhouses with his sons. He tells Eleanor that he now feels "sure-footed," and that Eleanor's public appearances, Louie's "shenanigans" and his own written statements have kept "his head above water." In a private moment, Franklin and Eleanor, who are distant cousins, discuss with amusement how their respective families opposed their marriage. Franklin believes that he made the better bargain and admits that he was too haughty in his younger years. Eleanor confides that she was an awkward adolescent who felt unloved, until Franklin made her feel "needed." Their daughter Anna, who has been unhappy and rebellious, abruptly interrupts their conversation. When Eleanor confronts her, Anna admits she feels left out, and she, Eleanor and Franklin agree that they need to talk to one another more often. In January 1924, the family is back in New York City, where Eleanor is gaining confidence as a public speaker. The controlling Sara, who considers politics "tawdry," urges Franklin to live a quiet life of luxury at the family's Hyde Park mansion and to give up trying to make the world the "same for all people." She reminds him that the wealthy serve the world through noblesse oblige , but he retorts that the idea is another name for indifference. An argument ensues, in which she supports herself by claiming that his cousin, President Theodore Roosevelt, died because of ambition of the people around him, but Franklin will discuss the matter no more. He becomes more determined to lift himself out of the chair and walk with crutches. For the upcoming presidential election, a Catholic, Governor Alfred E. Smith, is hoping to run as the Democratic candidate, but must first combat strong anti-Catholic bias. Guessing that Smith might ask the highly respected, "Protestant, dry and rural" Franklin to make the nominating speech at the Democratic Convention, Louie suggests that doing so is a way for Franklin to prove to the world that he has a political future. However, Louie concedes, that there is the chance that Franklin could fail, because, as Eleanor points out, the speaker must be able to stand before the crowd for at least forty-five minutes. Franklin admits that, if asked, he "would have to go into training" to be able to walk to the lectern and stand that long. When Smith visits Franklin, after some seemingly idle conversation to determine Franklin's physical ability and political opinions, he asks Franklin to make the nominating speech. After Smith leaves, Franklin arranges to get a blueprint of the area of Madison Square Garden where the convention will be held, and he and Louie estimate that he will need to walk on crutches ten steps to the podium. "Work hard," Louie advises. "They're liable to be the biggest ten steps you ever took in your life." On the night of the convention, Franklin has James roll his wheelchair near the podium, having joked to his son earlier that if he falls, "be sure to pick me up in a hurry." After the chair comes to a stop, Franklin uses his hands to place his braced legs into position and then rises, as the hall becomes quiet. He walks the ten steps with deliberation and when he arrives at the podium and hands James his crutches, the crowd cheers.