First Appearance: Young Men #24 (December 1953).
Appearances: Young Men #24-28, Captain America Comics #73-75, Captain America #153-156, 231-236, 281.
Years Active: 1955-1956, a short stint in the present (see below).
Steve Rogers (not his birth name) idolized Captain America (I) as a boy, and on hearing that Captain America had been killed at the end of the war dedicated his life to researching his hero. In a German records storehouse he discovered the formula to the Super-Soldier Serum that had created the first Captain America. The man told certain American government officials that he had the formula for the Serum, but refused to reveal it to them, wanting to become the new Captain America himself. The man then went through the government files on Captain America (I) and renamed himself "Steve Rogers" and had himself cosmetically altered so that he was an exact double for the original Steve Rogers. However, the Korean War ended and the government withdrew their support from the man.
The man now known as "Steve Rogers" then went to work as a teacher, befriending a student, Jack Monroe who had a similar interest in Captain America. In 1955, when the Red Skull (II) held the United Nations hostage, "Rogers" injected himself and Monroe with the Serum; the pair became Captain America (IV) and Bucky (III). The duo went on to fight crime, but without the exposure to the vita-rays that Captain America (I) had received, the Serum began to drive the two insane. They were finally captured by the FBI in 1956 and put into suspended animation.
The pair was revived in the modern day but were defeated by Captain America (I). They were again put into suspended animation, but eventually fell into the hands of the supervillain Dr. Faustus, who warped their minds; Faustus made Captain America (IV) the "Grand Director" of the "National Force," a racist hate organisation. When they came into conflict with Captain America (I), they were defeated, and Captain America (IV) committed suicide.