Well, sure. The go-to plot point is to think, "Steve Rogers is Captain America, and it has ever been thus!" Alas. you're fooling yourself. There's been many a Cap in the last few decades. These are just some of the ones we knew about:
5. William "Spirit of '76" Nasland
When Cap and Bucky "died," this is the guy Harry Truman tapped to wield the shield. As an expat member of the Crusaders (Great Britain's answer to the Invaders) I'm sure Bill was a great guy. I'm sure he'd like to be remembered as "the guy who saved John Kennedy's life, allowing him to run for president." Unfortunately, he will instead be remembered as "the guy in the tri-cornered hat who led the extremely ironically named 'All Winners Squad.'"
4. Jeffrey "Patriot" Mace
After Bill '76 came Jeff, a Daily Bugle reporter who led the Liberty Legion, whatever that may have been. Jeff was one of the few superheroes to die of old age, with Steve Rogers sitting at his side, thinking, "Wow. My inspirational life choices may have been questionable. Whoof."
3. John "USAgent" Walker
We all know John, John of Thunderbolts by way of Alpha Flight. John was the guy who took the shield after Steve quit in protest of Ronald Reagan's political posturing. Who doesn't remember that? What? Anyone, except old people? Whatever. Enjoy your "Nintendos" and "Super Mario Brothers," while the rest of us savor that sweet "Ms. Pac-Man" action.
Apparently, this person believed he was Captain America for several minutes. Anyway: hammer through the chest! Moving on!
When Steve Rogers left the Cap persona behind to fail to fight in Vietnam and become Nomad, said persona was assumed by "Roscoe." This well-meaning dude gave his all, but he ended up dying by– yikes!– crucifixion, with the Red Skull sending the message that any more "fake" Captains would end up the same way. Message received, mein herr. Please willkommen your buddy, Steve Rogers, Just let me know where you'd like your ass sent.