James "Bucky" Barnes is the protégé and childhood friend of Captain America, and a member of an elite special unit of Allied soldiers formed in World War II known as the Howling Commandos. He was assumed dead after falling off of Arnim Zola's Train. However, Bucky was able to survive the tragic fall, thanks to Zola's experiments. HYDRA subjected him to brainwash treatment as a candidate for the "Winter Soldier" program. Under HYDRA's control, Bucky would be responsible for countless assassinations including political parties. Bucky became a formidable fighter and an even more ruthless killer. His experiences with the KGB would earn him the name of The Winter Soldier.
Captain America: The First AvengerEdit
After the Pearl Harbor attack, Bucky enlisted in the US army and assumed the title of Sgt. Barnes. The day before his shipment out to England, Bucky helped his friend Steve from being beat up by a bully by kicking him in the groin. Bucky and Steve then went to the Stark Expo on a double date, though Bucky was having fun, Steve was interested in enlisting for the sixth time. Despite Bucky's protests Steve still went through with it but said goodbye to Bucky before doing so. Bucky and his unit, the 107th, then shipped to England the next day.
A year later, Bucky and his unit consisting of 200 men went up against a Nazi group named HYDRA lead by Johann Schmidt at the orders of the SSR but 150 of the men were either killed or captured while 50 barely escaped. Bucky and the Howling Commandos were among the captured. Bucky was taken to a prison where he was forced to work to design rockets called Valkyries, but it eventually became too much and he was taken to an isolation clinic for interrogation. But a few days later Steve (who had become Captain America) infiltrated the base, freed the prisoners and eventually Bucky too. During the escape Bucky and Steve encountered Schmidt and Zola but were able to escape them and the facility before it blew and walked all the way back to base, 30 miles out.
Later, Bucky, Captain America and Gabe Jones zip line on to the top of a HYDRA train. Bucky takes Captain America's shield and blocks him while he's down, but he does not have the upper body strength to hold on to it, and when he gets hit; it shoots him out the side of the train and Cap is unable to save him, causing him fall into a icy river below.
Captain America: The Winter Soldier
Barnes survived the fall, due to Zola's testing on him during his capture, and was missing an arm. He was found by Soviet soldiers some time later. He eventually ended up in HYDRA custody. In the care of the newly recreated HYDRA now working underneath SHIELDs nose, Barnes underwent further experimentation at the hands of Arnim Zola and various other doctors Removing the remnants of his severed arm, the doctors replaced the missing limb with a prosthetic one. Bucky was also subjected to multiple mind control methods to keep him under their command.