The movie starts in 2011 in the Artic. A car drives up to a big clearance site to see what's going on. A man says that they have discovered a large aircraft of some sort as the ice covering had just fallen into the ocean. The men cut a hole into the top of the ship and investigate. They are walking around when they come up to a large frozen block covered by snow. They wipe the snow away and a red, white and blue item with a star in the middle is revealed.
It cuts to Tønsberg, Norway, March 1942. Two men in a church seem afraid of some invasion and claim that some artifact is in danger. A tank busts through the wall and a man (Johann Schmidt) walks out. He asks the men where the artifact is and the men refuse to tell. Schmidt moves up to a picture of a tree and explains it is the Tree of Life and is an ancient Norse belief. He goes up to the tree looks for something finds it and then removes a block. He opens the top of the box and a light emerges. He shuts the box and shoots the men, driving off in the distance.
We then see a small and puny man (Steve Rogers) try to join the army only to be rejected as he is too weak. Let down Steve goes to the cinema to see a movie. Before the movie an ad about the army is played and a kid complains. Steve assaults the kid and is beaten up as he is smaller. He is saved being further beaten up by his friend James 'Bucky' Barnes. Bucky who has just joined the army takes Steve to an exposition of the future showing what future technology might look like. There is an army enlistment center their and Steve tries to enlist again. When Steve tries to enlist a doctor comes in (Dr. Abraham Erskine). Erskine sees that Steve is very dedicated in joining the army so he gives Steve a chance.
Steve is trained in the American army by Col. Chester Phillips and Peggy Carter. They and Dr. Erskine test him for a Super Soldier experiment. Through the testing they see that Steve is unselfish and will willingly risk his life to save another's. Therefore Steve is chosen to be part of the Super Solider experiment.
In Europe Johann Schmidt and Arim Zola are working on a way to harness the power of the artifact that they found (the artifact turns out to be The Tesseract). Using a machine made by Zola Schmidt harnesses the power of The Tesseract.
Steve is taken to a place where Howard Stark has built a machine that with Dr. Erskines Super Soldier Serum turns someone in to a 'perfect' human and magnifies all of their personality aspects. They place Rogers in a machine and inject him with the Super Soldier Serum they use the machine to make the serum work. Rogers emerges 6 foot 4 inch and very muscular. An onlooker (Heinz Kruger) uses the distraction of Rogers to shoot Erskine and steal the Super Soldier Serum. Rogers chases after Kruger discovering his new power. Kruger tries to kill innocent people to distract Rogers. Rogers saves all the people and keeps on chasing after Kruger. Kruger enters a submarine and tries to escape. Rogers takes Kruger out of the submarine and asks who he is. Kruger replys 'The first of many' and takes a suicide pill.
Hitler sends an envoy to inspect Schmidt's lab (as Schmidt works for Hitler). The men inspect Schmidt's weapon room where Schmidt is keeping a very powerful weapon (powered by The Tesseract). They find out that Schmidt has made smaller versions of this weapon for his soldiers. They also find out that Schmidt is plannig to destroy all of the capital cities in the world using the Tesseract (by accident). When they find that out Schmidt kills them.
Due to his heroic acts Rogers is named Captain America and is placed on a play to promote people enlisting in the American army. This campaign is very successful but upsets Rogers as it means he can't fight the war.
While Rogers is at a war camp he hears that half of the troops there have been captured. So Rogers escapes with Peggy to save the prisoners. It turns out the captors are H.Y.D.R.A and that they are running test on the prisoners. Rogers frees the prisoners by taking down all the guards. While the prisoners are escaping Rogers comes face to face with Schmidt who fight him. After the fight Schmidt reveals that he was the first test experiment of the Super Soldier Serum and that it destroyed his face and made him completely evil. Schmidt removes his face to reveal he is actually a hideous being with a red skull (therefore he is called Red Skull). Schmidt and Zola flee from the camp. While leaving the camp Rogers finds a map of all the H.Y.D.R.A bases.
Rogers and a team of soldiers he saved form a group called The Howling Commandos to fight against H.Y.D.R.A. The Howling Commandos set off to destroy all the H.Y.D.R.A bases and Red Skull tries to stop them. They destroy all the bases but one (Schmidt's main base). During one of the final mission they attack a train with Arim Zola on it. During the attack Bucky is killed by falling off a cliff. The Commandos capture the train and Zola. They take Zola back to head-quarters. There Zola is question and they find the location of Schmidt's main base.
The Commandos and the American army launch a full scale attack against the base and destroy it but Schmidt escapes on board a large plane which is set to destroy all of the capital cities of America. Rogers manages to jump on to the plane and take on Schmidt. Schmidt easily beats Rogers and in his moment of glory Schmidt shows Rogers what is powering the plane: The Tesseract. Upon touching The Tesseract with bare hands Schmidt disintegrates and The Tesseract burns a hole in the floor of the plane and falls into the sea. Rogers sees that the plane is on collision course for New York City so he diverts the plane and crashes in to The Artic. The plane and Rogers are frozen over.
Rogers wakes up to find himself in an apartment in the middle of New York City but he notices something strange about the apartment: a radio is playing a baseball game that was on a while ago. He opens the door of the apartment to find he is in a studio. He burst out of the studio to find himself in a strange building with advanced technology. He runs out of the building and sees that he is in Times Square and all the buildings and cars seem to be really advanced. He is stopped by a blockade of cars and Nick Fury approaches him. Nick Fury tells Rogers that he has been frozen for 70 years and that the year is 2011.
Steve Rogers is in a gym by himself and is punching a boxing bag. Nick Fury approaches him and tells him that he has a mission for Rogers. Rogers mission is to help save the world.
- Chris Evans - Steve Rogers
- Hugo Weaving - Johann Schmidt
- Sebastian Stan - James 'Bucky' Barnes
- Hayley Atwall - Peggy Carter
- Dominic Cooper - Howard Stark
- Tommy Lee Jones - Chester Phillips
- Neal McDonough - Timothy Dugan
- Stanley Tucci - Abraham Erskine
- Kenneth Choi - Jim Morita
- JJ Feild - Montgomery Falsworth
- Derek Luke - Gabriel Jones
- Bruno Ricci - Jacques Dernier
- Samuel L. Jackson - Nick Fury
- Johann Schmidt references Odin's chamber moments after taking the Tesseract.
- The Stark Expo theme introduced in Iron Man 2 ("Make Way for Tomorrow Today") is heard after Howard Stark's presentation at the 1942 World's Fair.
- Stark presents an early version of the Repulsor technology his son would perfect in Iron Man.
- When Steve Rogers is injected with the Super Soldier Serum, the film cuts to a close up of his eyes opening wide, a shot better known in association with the transformation of the Hulk. The film The Incredible Hulk ties Bruce Banner's gamma ray research into trying to re-create the super soldier serum, which was destroyed here.
- Tony Stark had a Captain America shield prototype in his lab in the two Iron Man movies. Stark's father, Howard, is depicted here designing the shield and Captain America's armor. Tony Stark also mentions in Iron Man that his father worked on the Manhattan Project, which ties into his World War II activities depicted here.
- The portal The Tesseract created that caused the Red Skull to vanish is the same as those seen in Thor in which it was used to teleport to different realms.