In the mid-1990s, comic book sales were declining drastically in the wake of the collapse of the comics speculator bubble. Belatedly people realized that comics were not an "investment", and the first issues the comics companies were printing millions of copies of weren't, in the end, going to be worth much more than cover price (if even that). By some accounts two thirds of comic book stores closed during this period, and in 1997 Marvel comics declared bankruptcy, though they continued to publish comics. (They eventually exited bankruptcy and after a few hit superhero movies were later bought by Disney)
In 1996 Marvel decided to outsource the production of some of their comics to some of the hottest artists in comics, who had gone on to set up their own studios. Certain characters were removed from the shared Marvel universe in favor of the "Heroes Reborn" universe, and the artists and writers were given carte blanche to do whatever they wanted with the characters. Marvel soon pulled the plug on the experiment, and after 13 issues the characters were returned to the Marvel universe.
This was not a good year for Captain America. The prior year Mark Waid and Ron Garney had been revitalizing the book, doing excellent work. The "Reborn" issues varied from awful (under writer-artist Rob Liefeld) to mediocre (under writer James Robinson). How bad were they?
In this version of Cap's history, Cap was taken out of commission by his own government, because he opposed the bombing of Japan with nuclear weapons. Chuck Austen tried to introduce this same idea into the proper history of the Marvel universe a few years later. It was ignored. It was a bad idea. (And the art stunk too.)
But as I said, after 13 issues Marvel pulled the plug on it, gave us Captain America Volume 3, put Waid and Garney back on the book, and they pretty much picked up where they left off. The whole thing is pretty much forgotten, except that Cap's alternate-Earth sidekick Rikki Barnes is still running around for some reason.