Steve Rogers was the original Captain America during the Second World War. He no longer operates under that identity, however, as it was passed on to others after he was presumed to have been killed during the war.
Steve Rogers was unfrozen by S.H.I.E.L.D. and taken to New York City, where they attempted to help him adjust to life in the 21st Century. S.H.I.E.L.D. decided to not continue to use Rogers as an active agent since they already had a Captain America (and also because Rogers came off as a bit senile); however, Rogers still kept his signature shield and continued to carry guns on his person 24/7. Rogers rented an apartment in the city with two roommates named Chuck and Danny.
Steve Rogers met Tony Stark, who took an interest in Rogers and decided that he could have some fun and make a few bucks on the side by entering Rogers in an underground fight club. The two made quite a bit of money, as Rogers went through multiple opponents, but the gig didn't last long and the two went their separate ways.
While walking through the streets one day, Rogers heard someone giving an anti-nationalist speech and saw him begin to burn an American flag. Rogers was infuriated with him, a masked man calling himself the Flag-Smasher. Rogers found himself unable to do anything to physically stop the Flag-Smasher and his followers, but the two did have a very loud debate. Soon after this, Flag-Smasher held hostage with a bomb threat a meeting of patriotic citizens. He began to spew forth his own anti-nationalist rhetoric until Rogers was able to sneak in and defeat him.
Upon hearing that the original Captain America was still alive, an old Nazi scientist who was a personal enemy of Steve Rogers named Baron Zemo went to New York City to eliminate him. At first Zemo tried to use a laser cannon to kill Rogers, but this proved too difficult and he was defeated by Rogers. Zemo, who had become severley senile since the wartime period, planned to kill Rogers by poisoning him with a bratwurst, so he set up a bratwurst stand right outside of Rogers' apartment building and waits for him there every day, always inviting him to purchase a bratwurst. He has perhaps since developed a larger feud with the man operating the hotdog stand across the street.
Rogers was present during the bust on Constrictor's massive weapons auction, fighting alongside others including Daredevil, Spider-Man, Moon Knight, and the Punisher. Rogers was the one responsible for putting Constrictor in a coma by ricocheting his shield off of a wall and hitting him in the back of the head.
During the standoff in Central Park between the Six Fingers of the Right Hand and various New York vigilantes, Rogers took up a positing at the top of a pine tree with a machine gun. He fought with the ninja named One-Eyed Jack, who was able to sneak up on Rogers despite the fact that he was perched on top of a Christmas tree.