Full story
The film opens in the present day, with a team in the Arctic finding an old aircraft buried in the ice. Inside is a round shield. Then the story jumps back to 1942. In occupied Norway, Nazi officer Johann Schmidt steals the Tesseract, a blue cube with almost godlike power. Schmidt runs Hydra, Hitler's science division, and he is already planning to outgrow the Führer himself.
In New York, Steve Rogers is skinny, asthmatic and full of health problems. He tries to enlist again and again and gets turned down every time. At the Stark Expo, Dr. Abraham Erskine overhears him and gives him a shot. During training, Steve throws himself on a dummy grenade to protect the others, and that sells Erskine. With the super-soldier serum and Howard Stark's vita-rays, he steps out of the chamber taller and far stronger. Moments later, one of Schmidt's spies kills Erskine, and the last dose of the formula is lost in the chase.
Without the scientist, the Army won't risk its only super soldier. Steve becomes a stage version of Captain America, selling war bonds in a flashy costume. In Italy in 1943 he learns that the unit of his best friend, Bucky Barnes, has been captured by Hydra. With help from Peggy Carter and Howard Stark, he goes in alone, breaks into Schmidt's factory and frees hundreds of prisoners. There he sees the villain's real face: the Red Skull.
Steve puts together the Howling Commandos, gets his vibranium shield and starts taking down Hydra bases one by one. His romance with Peggy grows slowly. On a mission aboard a train they capture scientist Arnim Zola, but Bucky falls into a ravine and is presumed dead. Using what Zola tells them, Cap storms the last base and boards Schmidt's giant bomber, loaded with weapons meant for American cities.
In the fight on board, the Tesseract breaks loose, opens a portal into space and pulls the Red Skull in. The cube drops into the ocean. With no way to land without hitting New York, Steve talks to Peggy over the radio, makes a date to go dancing and crashes the plane into the Arctic. He wakes up in a room dressed up like the 1940s, spots the trick through an old ballgame on the radio and runs out into Times Square. Nick Fury tells him he has been asleep for almost 70 years. What happens to the Tesseract and Hydra is left open and comes back later.