Charles Lindbergh risks his life to complete his historic flight from New York to Paris.

In 1927, in a hotel near New York's Roosevelt Field, air pilot Charles A. "Slim" Lindbergh has been waiting for seven days for the rain to stop, so that he can embark on what he hopes will be man's first successful nonstop trans-Atlantic flight to Paris. While Lindbergh lies sleepless, his friend, B. F. "Frank" Mahoney, guards his hotel room door from the numerous reporters who have waited with him for a break in the weather. In his room, Lindbergh reminisces about his former days as an air mail pilot flying over the Midwest: On a wintry night flight to Chicago, Lindbergh lands his antiquated De Haviland in a tiny air field to gas up. Although snow seems imminent, Lindbergh takes off, unaware that the Chicago landing field has closed due to snow. While in the air, Lindbergh's plane ices up and stalls, forcing him to parachute out with the mailbag. Continuing his journey by train, Lindbergh meets a suspender salesman who, recognizing he is an aviator, reports that two airmen died competing for the Orteig prize to be awarded to the first pilots to fly across the Atlantic nonstop. His interest piqued, Lindbergh calls Columbia Aircraft Corporation in New York City from the diner at St. Louis' Lambert Flying Field. Pretending to represent a group of prominent businessmen planning to buy a plane to compete in the trans-Atlantic race, Lindbergh is quoted the price of $15,000 for a Belanca plane. For the next six weeks, Lindbergh proposes his idea about entering the competition to St. Louis financiers. Eventually, with the help of his flying student, Harry Knight, Lindbergh meets with bank president Harold Bixby and other prominent St. Louis citizens. He explains to the group that, according to his calculations, flying nonstop, he can cross the ocean in forty hours in a single-engine plane by stripping the craft of all non-essential weight, thus allowing room for extra fuel tanks. The men are excited by Lindbergh's vision and create a name for the plane, Spirit of St. Louis . With a $15,000 check provided by them, Lindbergh proceeds to New York, but upon arriving there, is told by Columbia's president that the company will not sell the plane unless they choose the pilot. Dispirited, Lindbergh returns to St. Louis, where his sponsors immediately send him to San Diego to check out a small aircraft factory, Ryan Company. There he meets Frank, the president who promises to build a plane in ninety days. At the factory, Frank, Lindbergh and Ryan's chief engineer agree upon a design that puts the gas tank in front. Although it blocks Lindbergh's forward view, he is confident that he can use side windows and a periscope to compensate. To further decrease the weight, Lindbergh refuses to install all heavy indicator panels and plans to navigate by "dead reckoning," using the stars, sun and magnetic field. In the race to complete the plane ahead of schedule, workers at the factory agree to work twenty-four hour shifts. Meanwhile, a radio broadcast reports that a team of two pilots, who were vying for the Orteig prize, were killed flight-testing a plane. The Ryan plane is completed in sixty-three days, but it seems all for nothing, as two French fliers competing for the prize take off for New York. Confident that the pilots will succeed, Lindbergh flies the Ryan to St. Louis, where he apologizes to Bixby about losing the prize money to the French fliers, thus depriving his backers of the opportunity to recoup their investment. However, Bixby reports that the Frenchmen, now missing, are believed to have gone down from ice on their wings. Although other pilots are preparing to attempt the crossing, the businessmen are reluctant to risk Lindbergh's life. Determined to carry on, Lindbergh explains that the dead pilots would understand his resolve and proceeds as planned. At the New York hotel, where reporters type that he is sleeping like a baby, Lindbergh breaks out of his reverie and worries about building enough speed to take off in the mud. To decrease the weight of his plane, if only by a pound, Lindbergh unpacks his toothbrush, razor and extra shirt. He also unpacks the St. Christopher medal given to him by his student, Father Hussman, and reminisces how the priest's special prayers for every occasion seemed to compensate for his poor flying skills. Finally, unable to sleep, Lindbergh goes to the airport, where his plane waits, filled with three hundred gallons of gas. To decrease the plane's weight by twenty pounds, he eliminates the parachute. Limited space in the compartment necessitates placing the magnetic compass in an awkward position, so he determines that he needs a small mirror to see it. From the crowd waiting to watch the take-off, a young woman offers her mirror, which is then glued into place. Surreptitiously, Frank slips the St. Christopher's medal into Lindbergh's lunch bag. After a risky take-off, during which Lindbergh barely tops the trees, he discovers he has a stowaway, a fly, and passes time by calculating whether the insect flying within the plane adds weight. Every hour, Lindbergh switches fuel tanks to keep the load balanced. After passing over Cape Cod, he realizes his foot is numb and that he has not slept in twenty-eight hours. This prompts memories of sleeping on railroad tracks, short bunk beds, and under a windmill. When Lindbergh begins to doze, the fly, which he named "Jasper," awakens him by alighting on his face. Passing over Nova Scotia, Lindbergh spots a motorcyclist below and remembers his own Harley-Davidson, which he traded for his first plane on which he taught himself to fly. Eleven hours from New York, and with 1,900 miles of open water to cover before reaching Ireland, Lindbergh sees mountain peaks and wonders if the downed pilots are lost there. His own dangerous stunts come to mind and he recalls performing in a "Flying Circus." During his sixteenth hour of flight, as darkness falls, he worries that the plane's cylinder might crack from the cold. The sight of a "white ship," which he soon realizes is an iceberg, is evidence that he is near the Arctic Circle. Exhausted, he longs to land on one and sleep, and remembers the time he landed an old clunker of a plane at Brooks Field army base. After eighteen hours of flight, the plane's wings ice up, and when the engine stalls, he turns the plane toward warmer air. As the stalled plane begins to plummet, he prepares to bail out, but the ice breaks off and the engine resumes running. Upon returning to his course, Lindbergh discovers that his compass has become inoperable, thus forcing him to resort to flying by the stars. By dawn, he is so tired that he cannot do calculations and falls asleep, causing the plane to circle and descend, but sunlight reflecting off the mirror awakens him in time to regain control of the plane. A seagull alerts him to the nearness of land, and he soon realizes that he has reached Ireland ahead of schedule. When he prepares to eat his sandwich, he finds the St. Christopher's medal and hangs it on the dashboard. At the coast of France he turns northeast to follow the Seine River, noting he has only ninety-eight miles to go. Anxiety strikes when his engines again cut out, until he realizes he forgot to switch gas tanks. With a flick of the switch, he remedies the problem and the plane continues. Evening falls and he sees the lights of Paris. Flying toward Le Bourget airfield, he is bewildered to see spotlights and crowds of people. Exhaustion causes him to panic as he lands and he cries out one of Father Hussman's prayers, "Oh, God help me!" On the ground, hordes of people rush to Lindbergh, blind him with camera flashes and carry him triumphantly to the hangar, to which others are dragging his plane. Tired and confused, Lindbergh eventually realizes that the crowd is cheering for his great achievement. Upon Lindbergh's return to New York, the celebrations continue with a huge parade in his honor.