The Marvel Cinematic Universe finally seems to be on the brink of getting a long-term new Captain America: Sam Wilson (aka the Falcon), the rightful heir to the shield.
Spoilers ahead for Disney Plus's The Falcon and the Winter Soldier episodes 1-5.
Sam, however, isn't the first person to take up Cap's name and shield after Steve Rogers' 'he-lived-happily-ever-after (in the past)' moment in Avengers: Endgame. The Falcon and the Winter Soldier has introduced Cap's initial substitute: John Walker, played by Wyatt Russell (son of Guardians of the Galaxy Vol. 2's Kurt Russell/Ego the Living Planet).
After Sam wrestled with his conscience, decided the time wasn't right for a Black Captain America, and donated the shield to the Smithsonian, the government had other plans and by the end of the first episode, Walker is installed as the new Cap ... much to Sam's and Bucky's - and now the world's - chagrin.
But who is John Walker, how did he become Captain America in the comic books, and why was his tenure so short and controversial? And how could his story playing out in The Falcon and the Winter Soldier affect the future of the MCU?
Here's all you need to know.
Who is John Walker?
Back in the '80s, Steve Rogers was rethinking his role as Captain America. He had briefly given up that identity before to become the 'Man Without A Country' Nomad, but this time was a little different.
Angered at both the government becoming more hands-on and the tasks he was being asked to perform, Rogers resigned, handing in his shield and costume. Instead of sporting the traditional costume, he took up a black, white, and red ensemble simply calling himself 'The Captain.' No longer feeling like an extension of America, Captain became a standard crime-fighter.
However, the Commission on Superhuman Activities, the government task force ordered to oversee Cap's duties, wasn't so keen on losing America's personal superhero, so they searched to find a replacement willing to don Cap's shield and costume – and to follow their strict ideals.
Enter John Walker.
Walker, a soldier stationed at Fort Bragg, asks for the help of the villainous Power Broker to give him superpowers. After getting those powers and participating in underground superhuman wrestling leagues, Walker catches the eye of a publicist, who tells him he should try and be a superhero instead.
Now calling himself Super Patriot, Walker uses his new super-strength to begin his own career as a right-wing version of Captain America. Walker's publicist begins making a series of high-profile fights against supposed pro-Steve Rogers activists, but who are actually actors hired to make Walker look like a good choice to replace Rogers.
Funny thing is that the scheme works, and Walker is hired as the replacement Captain America. However, things quickly go south. First, Walker is sent by a rogue agent to help hunt down political rivals to the ruthless regime of a South American dictator, and causes this new Cap to become bitter. Walker's violent methods as Captain America lead terrorists known as the Watchdogs to kill his parents after his secret identity is revealed on global television.
Walker's strict orders from the CSA force him to miss their funeral and he quickly becomes extremely unstable and actually murders numerous members of the Watchdogs. As a result, he's captured by the fascist Flag-Smasher - but ironically rescued by Steve Rogers under his Captain moniker.
Interestingly enough, Walker is tricked by Cap's old nemesis the Red Skull into confronting Rogers in Washington, DC – but the two heroes quickly realize what's happening. After Walker runs roughshod through Red Skull's henchmen, the two Captains bring down the arch-villain himself. After this, Walker gives Steve back the Captain America shield and uniform, and takes up Steve's black, white, and red 'Captain' uniform as US Agent, complete with a new, matching shield.
How does John Walker fit into the Marvel Universe?
Soon after becoming US Agent, Walker became a cornerstone of the Marvel Universe throughout the '90s, having been a part of Avengers West Coast and the core Avengers team. Walker also served as an agent of SHIELD, a member of the Invaders, and even a member of the Canadian team Omega Flight. Along the way, his shield was replaced with an energy-based one that would pop out of his bracers.
Tragedy struck when Walker was dismembered by the villain Nuke, using Odin's spear. A few years later, while using a wheelchair and prosthetic arm, Walker became the overseer of a brand-new Thunderbolts program with Luke Cage acting as the field leader of a group of former villains trying to be rehabilitated into heroes.
His time with the team would oddly enough lead Walker to another dimension where he would regain the use of his limbs through a magical source.
Walker will co-star in the upcoming United States of Captain America limited series, in which Steve Rogers, Sam Wilson, Bucky Barnes, and the US Agent all team up for a road trip adventure celebrating the 80th anniversary of Captain America's 1941 debut.
How does John Walker fit into the MCU?
As we saw in The Falcon and The Winter Soldier, John Walker was the government's choice to replace Steve Rogers as Captain America, which was against the wishes Steve expressed in Avengers: Endgame.
Rather than a Super Soldier, Walker was a young soldier and family man who is inspired by Captain America's heroism and legacy. He earned the honor of becoming Captain America as a decorated war hero who scored at the highest levels of physical and strategic testing.
Like in comic books, Walker had a partner - Lemar Hoskins (aka Battlestar), one of his closest military allies. In comics, Hoskins was one of several unnamed sidekicks Walker employed in his early hero days before becoming Captain America who was chosen to be the new Cap's sole partner, first being given the name 'Bucky' in honor of Steve Rogers' original sidekick.
However, as late writer Dwayne McDuffie informed Hoskins' co-creator Mark Gruenwald shortly thereafter, 'Buck' or 'Bucky' can be considered archaic but still offensive slurs for Black men. Gruenwald and McDuffie worked together to revise the concept, and Battlestar - a full-fledged partner for Walker's Cap along the lines of the Falcon - was born.
Sam is seen not accepting the role of Captain America and remaining as the Falcon at first, but the fourth episode of The Falcon and the Winter Soldier began to reveal where the Walker storyline is going and given his comic book history, inevitably was.
In the instantly controversial episode four, Walker has taken some of the still-mysterious Power Broker's Super Soldier Serum, which is an adaptation most mostly true to both of their comic book backstories.
And also true to Walker's comic book history, his violent tendencies come to full and shocking fore. Battlestar's death at the hands of the Flag-Smashers sends Walker over the edge, who in the final moments of the episode, beats and then murders a Flag-Smasher in cold blood with the iconic shield in full view of Sam, Bucky, and civilian witnesses. The final shot of blood dripping from the shield is being called the MCU's darkest moment by some fans.
In Marvel comic books, Walker is eventually treated for the side effects of the Power Broker's Super Soldier Serum that exacerbates his violent tendencies. In The Falcon and the Winter Soldier before his death, Lemar/Battlestar makes the point that possessing the power the serum provides seems to reveal their true nature rather than corrupts them, and episode five doesn't too much to suggest there's much good left in Walker.
So while comic book precedent suggests there's room for him to take up the mantle of US Agent as his own hero eventually, given the shocking last moments of The Falcon and the Winter Soldier's fourth episode, him getting to that place in the MCU would require some serious rehabilitation, and that would be - as has been a theme of the series so far - complicated.
In episode five, Walker is defiant and unrepentant about the murder and is seen creating his own shield after Sam takes it from him and the government strips him of his role of Captain America and kicks him out of the military.
That said, how much of Walker's mental state is him and how much of it is being manipulated by a new Marvel character introduced in episode five remains to be seen.
The Falcon and the Winter Soldier has so far explored the nature of Captain America and the legacy of Steve Rogers, and what it means to embody that role and carry the vaunted shield that comes with it. The starkly different ideology between Sam Wilson and John Walker has come to the ultimate climax, with Sam now on the precipice of finally assuming the mantle of Cap in the series finale.
Oddly enough, Sam Wilson was one of the candidates considered to replace Steve Rogers when Walker was first hired in comic books – but the CSA decided America wasn't ready for a Black Captain America. In fact, it would be many years before Sam took up Cap's shield in comics, and he was even preceded by a term behind the shield by Bucky, the Winter Soldier – his co-star on the show.
But Sam isn't actually the first Black man to operate as Captain America - in comic books or in the MCU. In fact, The Falcon and the Winter Soldier complicates the legacy of Captain America even further by introducing Isaiah and Eli Bradley, who have their own complex and tragic Marvel Comics history.
Whatever comes next, it seems very likely - and hopeful - that Sam Wilson will wind up in the mantle of Captain America longterm, even into future films.