Captain America - Every National Hero In Marvel Comics Explained
6. Captain America(s)
At the beginning of America’s involvement in World War Two, Steve Rogers was a kid from Brooklyn. He wanted to enlist in the US Army, but was rejected on medical grounds. A second chance came in a procedure called Project Rebirth – a US scientific experiment to create super-soldiers. It worked, but when the super soldier serum's creator Dr Abraham Erskine was assassinated, it died with him, leaving Steve Rogers the only living reminder of his work. Thus, patriotic mascot Captain America was born.
But Second World War patriotism didn't translate into Post-War America, and so the character needed amendments. The 1950s incarnation took on Communism amid the ongoing political tensions of the Cold War (although this was later retconned so that it wasn't actually Rogers); the Watergate Scandal disillusioned Cap from the US Government; and the Superhuman Registration Act turned him against the government entirely, kicking off Marvel's Civil War.
Steve Rogers isn't the only person to have taken up the shield however. On one of the many occasions Rogers resigns from the role, John Walker (then known as Super-Patriot) was assigned the part. He was unable to live up to the enormity of Rogers' reputation, and quit. Walker remained patriotic, dubbing himself US Agent.
The aforementioned 1950s Captain America was not actually Rogers - he was too busy being frozen in ice after crashing into the Arctic near the end of the Second World War. Three men filled the void left by Rogers' disappearance: William Naslund (also the similarly patriotic hero Spirit of '76, who'd end up being killed in an effort to protect JFK), Jeffrey Mace (formerly known as Patriot), and William Burnside (who eventually went a bit mad and returned as a white supremacist leader named Grand Director).
These heroes all lacked one thing: the serum that had empowered Rogers. The US Government attempted to replicate Erskine's experiment using 300 African-Americans volunteers, only one of whom saw moderate success. Isaiah Bradley did his part, liberating Nazi concentration camps wearing a stolen Captain America costume, but this was not looked upon kindly by the US army, who imprisoned and further experimented upon him, completely destroying his mind. His grandson Elijah would, however, go on to become another hero - this time called Patriot - in the Young Avengers.
Rogers' assassination at the end of Civil War once again left the shield open to a newcomer. This time, Rogers had the foresight to name a successor. Long time friend James Buchanan "Bucky" Barnes, his partner during World War 2 and himself frozen for a few decades, replaced Rogers. Unlike the always-unconscious Steve, Bucky had to deal with Hydra's brainwashing which turned him into a secret assassin called the Winter Soldier. His appointment as the new Captain America was the subject of some controversy, but he strove to make amends for his shady past nevertheless.
Rogers would eventually return due to a very convoluted plot regarding time travel and existentialism, but not for long. After losing the serum (long story), longtime friend and ally Sam Wilson (Falcon) assumed the mantle of Captain America, only recently surrendering it back to Steve once he regained his powers.