[2] The character is brought back from supposed death as the brainwashed assassin cyborg called the Winter Soldier (created by Ed Brubaker and Steve Epting) (Russian: Зимний Солдат, translit.

During the 2011 crossover Fear Itself, Barnes is injected with the Infinity Formula, which increases his natural vitality and physical traits in a way similar to (but less powerful than) the super-soldier serum used on Captain America.

[5] Following the character's debut in Captain America Comics #1 (March 1941), Bucky Barnes appeared alongside the title star in virtually every story in that publication and other Timely series, and was additionally part of the all-kid team the Young Allies.

Captain America and Bucky were both briefly revived, along with fellow Timely stars the Human Torch and the Sub-Mariner, in the omnibus Young Men #24 (Dec. 1953), published by Marvel's 1950s iteration Atlas Comics.

Retroactive continuity, beginning with The Avengers #4 (March 1964), established that the original Captain America and Bucky went missing near the end of World War II and were secretly replaced by then-U.S. President Harry S. Truman with successor heroes using those identities.

During the 2011 Fear Itself crossover, Barnes is killed but then quickly restored to life by the Infinity Formula, the same chemical that gave Nick Fury enhanced vitality and physical traits, and which itself was a weaker form of the super-soldier serum.

During this same time, newspapers and radio programs share news of a mysterious new hero called Captain America, a man who was turned into a super-soldier thanks to a special serum and technology developed by Dr. Abraham Erskine (codename: Dr. Reinstein) and his project Operation: Rebirth.

In the revised Marvel Comics canon, on Major Samson's recommendation, 16-year-old Bucky undergoes rigorous commando and special ops training under the direction of the British SAS in 1940.

In 1942, after the U.S. officially enters World War II, Rebecca is told that Bucky is now an active soldier in the European Theatre, having lied about his age to join the army.

During several World War II missions, Steve and Bucky work alongside Nick Fury and the Howlers, a group of US Rangers who are nicknamed the "Howling Commandos."

[18] After helping the local hero Black Panther against Nazi invaders, Steve Rogers is given a sample of vibranium, which is later used to create a discus-shield of a unique vibranium-iron alloy.

During this adventure, Bucky hides his true movements and plans by asking Fred Davis, a batboy for the New York Yankees, to temporarily wear his costume and impersonate him.

[21] In the closing days of World War II in 1945, when Bucky is 20-years-old, he and Captain America find the villainous Baron Zemo trying to destroy an experimental Allied drone plane.

[26] The Winter Soldier aids the escape of the mutant called Wolverine from the Weapon X laboratory that experimented on him against his will, bonding his skeleton with the indestructible metal adamantium.

[27] At some point, the Winter Soldier, who at times shows hints of his human personality, briefly shares a romantic affair with Russian operative Natalia Romanoff, the Black Widow.

Months after the team's formation, its members Iron Man (Tony Stark), Wasp (Janet Van Dyne), Giant-Man (Hank Pym), and Thor discover the frozen form of Steve Rogers.

[22] After being revived from suspended animation and learning decades have passed since his final battle alongside Bucky during 1945, Steve resumes his role as Captain America and joins the Avengers.

On Lukin's orders, the Winter Soldier launches a terrorist attack on Philadelphia, Pennsylvania, killing hundreds and recharging the damaged Cosmic Cube in the process.

director Nick Fury confirms the Winter Soldier's existence, and Steve sees evidence that the assassin is actually Bucky, still alive but brainwashed and unable to remember his true identity.

[45] The teenage Barnes decides to ignore this advice and follow his instincts when the time arrives, allowing his life turn out the way it should rather than risk causing unforeseen damage by changing history.

[48] Later, Bucky discovers Professor Zhang Chin intends to use the inert android body of the original Human Torch to create a virus to exterminate half the Earth's population.

[49] In the 2009–2010 "Captain America: Reborn" storyline, Barnes finds out Steve Rogers was not killed but has been trapped in a fixed position of time and space, a complex revenge plan enacted by the Red Skull.

[56] During the Fear Itself storyline, Barnes takes up the Captain America identity again, but is apparently killed in battle with the villain Sin (temporarily empowered by Asgardian forces as Skadi).

[28] After tracking them down, they learn the operatives were awakened recently by Ivan Kragoff, the villain called Red Ghost, and Lucia von Bardas, former Prime Minister of Latveria.

Once Sam Wilson begins his own plans to defeat Hydra, Namor tells Winter Soldier the time has come to remove his disguise and help their allies.

[72] IGN called Bucky Barnes one of the "most iconic superhero sidekicks of the Golden Age," writing, “this troubled soldier now wields the mantle of his mentor and fights injustice as the new Captain America.

In the House of M reality, James Buchanan Barnes is one of the United States government agents (alongside Mimic and Nuke) sent to Genosha to kill Magneto and as many of his followers as possible.

[88] In the Marvel MAX series U.S. War Machine, Bucky serves in the present day as Captain America, following the death of the Steve Rogers of this world.

[90] In Planet Hulk #1, Battleworld versions of Bucky Barnes and Steven Rogers are inspired by the heroism of Sam Wilson and join the Super Soldier program together.

[98][99] Additionally, Stan voices alternate timeline variants of Barnes in the Disney+ animated series What If...?,[100][93] and will reprise the role in the upcoming live-action film Thunderbolts*.