James Buchanan "Bucky" Barnes, also known as Winter Soldier and White Wolf, is character appearing in the Marvel Cinematic Universe, based on the Marvel Comics character of the same name. He is something of a composite character, as the White Wolf is a separate character in the Marvel Comics Universe.
James Buchanan Barnes was born on on March 10, 1917 in Shelbyville, Indiana; the eldest of four siblings. His family moved to New York during the Great Depression, as job prospects had grown thin in the Midwest. In September of 1930, the 13-year-old "Bucky" was walking home from boxing lessons at the Hell's Kitchen YMCA when he noticed a thin, sickly boy getting beaten up by bullies twice his size. Inspired by the kid's misplaced bravery, Bucky stepped in to help. The boy introduced himself as Steve Rogers, an orphan from Brooklyn. The two quickly became friends, as Steve's book smarts perfectly complimented Bucky's street smarts.
When the United States entered World War II after Pearl Harbor, Barnes and Rogers decided to enlist. While Rogers was deemed 4F due to his medical problems, Barnes easily passed his physical exam and completed basic training, becoming a Sergeant in the 107th Infantry Division. Prior to his first overseas deployment, Barnes visits Rogers, and they attend a Modern Marvels of Tomorrow Exhibit where a young inventor named Howard Stark is demonstrating his experimental propulsion technology. Over the next five month, Sgt. Barnes and the 107th Infantry fight in the European Theater while Rogers undergoes the training and procedures that turn him into the the super-soldier code-named "Captain America". The 107th is captured by the forces of HYDRA, the secretive Axis Powers research division commanded by Lieutenant General Johann Schmidt. Barnes is separated from the other prisoners as Schmidt and his right hand man, Dr. Zola, conduct experiments on him aimed at enhancing soldiers. When Rogers discovers that Barnes is missing and no rescue operation is being planned, he decides to enact his own rescue as Captain America, outfitted with weapons and armor modified by Stark, including a vibranium shield. Rogers liberates the prisoners, who quickly learn how to use the advanced HYDRA weaponry and form an elite unit, the Howling Commandos. Over the next two years, the Howling Commandos perform several successful operations against HYDRA. However, during an attempt to capture Zola, Barnes was shot and fell to his apparent death.
However, Zola's experiments on him when he was a prisoner enabled him to survive these normally fatal injuries, albeit barely. HYDRA scientists restored what they could of his body, replacing his unsalvageable left arm with a cybernetic limb made of a titanium alloy. HYDRA's new leadership had infiltrated S.H.I.E.L.D., the CIA, and the KGB - thus secretly running both sides of the Cold War. Barnes was given over to the KGB, who brainwashed him into being an assassin code-named the Winter Soldier. The Winter Soldier would be deployed for covert assassination missions and placed in suspended animation at HYDRA's Siberian base until his next mission. This slowed his aging, and also made him something of a "ghost story" among spies, assassins, and mercenaries. One of the Winter Soldier's earliest missions was in 1951, during the Korean War, where he fought a Super Soldier test subject, Isaiah Bradley. The Winter Soldier suffered serious injuries in this fight and barely escaped with his life.
In 1991, Howard Stark had been working on a new Super Soldier serum. The Winter Soldier was reawakened by Colonel Vasily Karpov to assassinate Stark and his wife, Maria, and steal his research. Howard's last moment was the confused reaction of noting his killer's resemblance to Sgt. Barnes, still looking as youthful as he did during the '40s. Karpov attempted to create other super soldiers who could be used similar to the Winter Soldier, but they proved unstable; Barnes had to evacuate Karpov and place the failed candidates in suspended animation.
The Winter Soldier was next reawakened in 2009, to assassinate a Nigerian scientist under the protection of Black Widow. Barnes completed his assignment by shooting through the Black Widow when she tried to shield her target. Romanoff herself survived, with a small scar on her hip to remind her of the encounter.
The Winter Soldier's next deployment was two years after Captain America had been awakened from his own suspended animation. Colonel Nick Fury had begun to suspect that S.H.I.E.L.D. had been infiltrated by rogue elements, and expressed this concern to one of his senior agents, Alexander Pierce. Pierce was in on the plot, so he ordered the Winter Soldier to assassinate Fury. Fury narrowly escaped the first attempted, but the Winter Soldier was able to track him down again and critically injure him. Before he could finish off the Colonel, he was fought off by Captain America, who forced him to retreat.
As Captain America, Black Widow, and their newest allies Sam "Falcon" Wilson and Agent 13 were branded fugitives by the conspiracy, the Winter Soldier was ordered to hunt them down. Cap recognized his old friend and sought to redeem him, while Barnes gradually began to remember his old life. Things came to a head when Pierce showed his hand, officially launching an uprising where several HYDRA controlled military and government agents launched a massive attack on Washington DC. During the battle, the Winter Soldier finally broke free of his conditioning and saved Cap from falling into the Potomac. The Battle of Washington ended with the defeat of the conspirators, with Pierce killed and several HYDRA infiltrators exposed and arrested, but the Winter Soldier escaped. He regained his old memories after visiting the Hall of Valor exhibit, which contained a monument to himself and his squadmates in the Howling Commandos. Anticipating that he will be hunted by people on both sides of the law, some of whom might want him dead, he spends the next two years living off the grid in Romania.
Although Captain America had hoped to quietly track down Barnes and restore his sanity, he soon found himself with bigger fish to fry. S.H.I.E.L.D. operative Deathlok had been tracking a HYDRA scientist, Dr. List, but found a larger HYDRA cell that the Avengers were called on to take down. And a rogue AI had attacked the European nation of Sokovia, causing massive collateral damage before the Avengers destroyed it. The death and destruction caused many to champion further government oversight among super-powered operatives, a move opposed by Cap but supported by Howard Stark's son Tony, who had become the armored superhero Iron Man. This leads to a UN conference in Vienna to discuss what form the proposed "Sokovia Accords" will take. This conference is disrupted by a terrorist bombing that kills many of the dignitaries, including King T'Chaka of Wakanda. T'Chaka's son, Prince T'Challa, secretly Wakanda's superhero champion Black Panther, vows to hunt down the guilty party and exact vengeance. Security footage implicates the Winter Soldier as the bomber. Suspecting that Barnes is being framed, Cap calls in some favors and tracks him down in Bucharest. Black Panther follows him and attacks the Winter Soldier, resulting in a massive free for all that spills into the streets until Cap and the Winter Soldier are arrested by War Machine and brought to a high security S.H.I.E.L.D. facility in Berlin. While Stark admonishes Rogers on the laws he has broken, the real bomber infiltrates the facility disguised as Dr. Theodore Broussard, a psychiatrist assigned to profile Barnes. Broussard recites a code that triggers a secret mental program within the Winter Soldier, and he breaks free of his restraints and goes on a rampage. Cap and Falcon eventually track him down, and suspect that Broussard is seeking the location of the Siberian facility where the other Winter Soldiers are being held. Seeking the aid of Hawkeye, Scarlet Witch, and Ant-Man, they head to an airport in Leipzig, but are intercepted by Iron Man, War Machine, Vision, Spider-Man, Black Panther, and Black Widow. A pitched battle between the factions ensues, with Iron Man's team gaining the upper hand until Cap's switch to a holding action to buy time for Rogers and Barnes to escape. Iron Man has the rebellious heroes locked up in The Raft, then receives a report of the real Dr. Broussard being found dead in his hotel room, which finally convinces him of the Winter Soldier's innocence. Once Captain America, Winter Soldier, and Iron Man arrive at the Siberian facility, finding all the other Winter Soldiers dead, the impostor identifies himself as Colonel Helmut Zemo. His family was killed in the Sokovia Incident, and he blamed the Avengers. As a normal human, he had no chance of destroying them by force, but he could drive them apart from within. He reveals his hidden trump card... a video that reveals that the Winter Soldier killed Iron Man's parents. Iron Man attacks the Winter Soldier in a rage, and Cap instinctively moves in to protect his friend. Iron Man destroys the Winter Soldier's cybernetic arm with his Uni-Beam, before Cap incapacitates him with his shield. Recognizing that the shield belongs to Iron Man, as his father made it, he leaves it behind as he and Barnes depart. With Barnes officially exonerated, Black Panther offers them sanctuary in Wakanda, where his sister, Shuri, removes the remaining HYDRA programming.
When Thanos arrives on Earth seeking to recover the remaining Infinity Stones and bring his view of "balance" to the galaxy, Barnes is called back into service. Black Panther equips him with a vibranium arm and dubs him "the White Wolf." The White Wolf joins the Avengers in the Battle of Wakanda, but is one of those "blipped" out of existence when Thanos acquires the stones. He is restored to existence five years later, after Thanos is defeated. Barnes is there to witness Rogers bequeathe the shield and mantle of Captain America to Falcon.
However, Falcon decides to donate the shield to the Smithsonian, under the belief that Captain America represents a moral high ground that nobody, not even him, can live up to at the current moment. This disappoints Barnes, as he feels this means that Cap had misjudged Sam. If he was wrong about Wilson being ready to inherit his legacy, perhaps he was wrong about Barnes deserving a chance at redemption. Though he had received a Presidential Pardon for his role in the Battle of Wakanda, and the final battle against Thanos, it was contingent on attending regular court-mandated therapy sessions. Barnes had been haunted by nightmares of his crimes he committed during his tenure in HYDRA, and had been compiling a list of those he wronged, hoping to atone for these actions individually.
Barnes and Wilson have a tense reunion after the US Government announces a new Captain America: John Walker. Neither man believes Walker is worthy of inheriting the shield, but Barnes reminds Wilson that this all would have been a moot point if Sam had accepted the shield in the first place.
Despite their tensions, the two agree to work together to pursue the Flag Smashers, a team of anarchists that have begun undertaking increasingly violent acts of terrorism. When it becomes clear that the Flag Smashers are using an old version of HYDRA's Super Soldier serum, Barnes decides they must seek the aid of a man who has spent much of his life trying to destroy it: their old adversary Zemo.