Oh Captain, my captain… – Walt Whitman
Captain America and Iron Man embodied everything that the Avengers were, and superheroes should be.
While Stark had to learn to become the man he was when he sacrificed himself to defeat Thanos and restore balance to the universe in Endgame, the sense of duty, honor, and loyalty, and a refusal to back down or surrender regardless of the odds that he was facing, were all part of who Steve Rogers was before he was given the super-soldier serum.
It was his heart and his unwavering determination that made him the ideal candidate for the supersoldier program and ensured that the ideals that he believed in, and his refusal to compromise would eventually rub off on, and change the world view of Tony Stark.
But does the super-soldier serum that flows through his veins have another, unforeseen benefit? Does it help him to live forever, and is Captain America immortal?
The First Avenger
Before he enters the Vita-Ray Chamber in Captain America: The First Avenger, the man responsible for creating the super-soldier program, Abraham Erskine tells Steve Rogers that the serum and the procedure merely amplify what is already there, which is why it was so important for them to find the right candidate.
If Rogers wasn’t who he was, would the serum have worked? If we believe what Erskine said, then it almost certainly wouldn’t and given what it did to the Red Skull, we don’t have any reason to believe that Erskine was lying.
As well as increasing his strength, stamina, and speed, the serum was responsible for keeping him alive and in a state of perfect suspended animation when he crashed into the ice in both the comic book and film mythology surrounding Steve Rogers.
The duration of his extended sleep might have varied between the time he was discovered in Avengers #4 and in The First Avenger (twenty years in the former and seventy in the latter), but in both instances, it was the super-soldier serum that enabled him to survive for as long as did in the freezing temperatures of the ocean-bound ice that he was trapped in.
Does The Super Soldier Serum Make Captain America Immortal?
No, it doesn’t.
Like you, we’ve heard the wild fan theory that because he was able to wield Mjolnir in Endgame and was gifted the power of Thor by the hammer, that when the lightning and the Godforce flowed through him and combined with the super-soldier serum it somehow made him immortal.
It’s a nice theory, but it doesn’t ring true in either of Captain America’s celluloid or ink and print worlds.
The same qualities that made Steve Rogers the perfect candidate for the super-soldier program made him worthy to lift Mjolnir, which he would have been able to do whether the serum was pumping through his body or not.
Rogers was always worthy of the program and he was always able to lift Mjolnir, a feat that isn’t dependent on physical strength but relies entirely on the size of, and what is in, the heart of the individual attempting to wield it.
While the serum doesn’t make him immortal, it does slow the aging process down, and this was made evident in the closing moments of The Iron Nail when Ran Shen used his power to strip Steve Rogers of the super-soldier serum, at which point the man who was Captain America began to rapidly age until his body caught up with time.
The serum might help to keep him young and in prime physical condition, but it doesn’t make him immortal.
At least, it doesn’t in MCU, where Loki has admitted that even Asgardians don’t live forever, and age the same way that humans do “give or take five thousand years”.
How Do We Know That Steve Rogers Isn’t Immortal?
In the closing moments of Endgame Steve Rogers reappears, sitting on a lakefront bench, after having elected to stay in the past and live the life he had earned a hundred times over with the woman he fell in love with the first time he saw her, Peggy Carter.
During the seventy years and some change that he spent as a working stiff, despite the fact that the super-serum was still flowing through his veins, he aged naturally, if somewhat slowly, which is why he looks like an eighty-year-old man when he meets Sam, to give him the shield and asks him to become the next Captain America.
Being old doesn’t mean that Steve Rogers isn’t immortal, and we’d agree that just because he looks old, it doesn’t mean that he won’t live forever if it wasn’t for The Falcon And THe Winter Soldier.
In the first season of the show that sees Sam finally accepts his role as the new Captain America, and James ‘Bucky’ Barnes abandons the Winter Soldier persona and becomes Sam’s new partner, both men mention that Steve is “gone”.
While it isn’t expressly stated that Steve Rogers has died, it is implied that he has passed away in every single one of the show’s six episodes.
If, as Bucky and Sam repeatedly state throughout the series, Steve is “gone”, then it means that the super-soldier serum, while making him faster and stronger than almost any other man alive, didn’t grant him the power of immortality.
The Immortal Legacy of Captain America
It isn’t the man who wields the shield who is immortal, it’s the shield and the legacy that it carries that lives forever.
Steve Rogers may be gone, but he has passed the shield, title, and the responsibility that comes with both to Sam Wilson, and when the time comes for Sam to step down, he’ll pass the shield and the name on to the person he chooses to replace him.
So, yes Captain America is immortal, but not in the conventional sense of the word.
The name and all that it can, and should represent is immortal as the men and women who step forward to assume the role that Steve Rogers created, play their part in ensuring that the legacy of Captain America will live forever.