James Buchanan "Bucky" Barnes is a fictional superhero appearing in American comic books published by Marvel Comics. Originally introduced as a sidekick to Captain America, the character was created by Joe Simon and Jack Kirby and first appeared in Captain America Comics #1 (cover-dated March 1941) (which was published by Marvel's predecessor) as the original and most well-known incarnation of "Bucky". The character is brought back from supposed death as the brainwashed assassin Winter Soldier, and later assumed the role of Captain America when Steve Rogers was presumed to be dead.