Steve Rogers (a.k.a. Captain America) is a main hero in the Marvel franchise by being part of the Avengers Initiative, being a super soldier, and being considered the first Avenger. As a kid, he got picked on a lot, but mainly because he was the one picking fights. Steve’s known for “hating bullies” and valuing honesty, loyalty to his friends, and doing what is right, no matter what it takes. He assumes the role of Cap in the movie Captain America: The First Avenger, where Steve starts as this scrawny kid who has health issue after health issue. His best friend is Bucky Barnes (James Buchanan Barnes), and he does everything he can to enlist in the war, yet he is not able to because of his health. However, one doctor takes a chance on him, and Steve is sent off to join the military.
He might not be the strongest, but he has the most heart, which is why they chose him to get super-soldier serum, because for someone who is good, it makes the good better. This is who Captain America is. From there, Captain America became the face of the war, trying his best to uplift the troops until he finds out his friend Bucky is a POW along with others. Steve puts a team together, and they go and rescue the POWs, risking a lot just to rescue Bucky. He and Bucky catch up before going on one more mission together because after Bucky falls off a train and dies, Steve gets frozen in ice before ending up in the future (2012).
The main ideal throughout his entire story is that when he heard there was a chance Bucky could still be out there and alive, he went out and did what he could to save him because they were together “‘til the end of the line.” This line does not fully come into play until Captain America: The Winter Soldier, where Steve finds out that Bucky did survive the fall from the train (he just lost his arm) and ended up as Hydra’s experiment with super-soldier serum. Near the end of the movie, Steve and the Winter Soldier fight it out, and it is only when he is being obliterated by his friend that Steve repeats this exact phrase to him. It causes Bucky to stop for a moment because it makes him remember who he is for a moment. The line signifies that the two will vow to fight alongside each other until their dying moments.
Throughout this movie, everything Steve does is to help Bucky, even if Bucky can not remember a single thing about his life. He is still Steve’s friend.
In Captain America: Civil War, Tony and Steve’s argument over whether the Avengers should work for the government or be their own institution causes the team to pick sides. During this movie, however, Bucky Barnes is framed for bombing the United Nations conference in Vienna. Only, Bucky was in a whole other country at that point. So why would someone frame him when he was healing from all of Hydra’s torture?
Natasha Romanoff (Black Widow) was the only Avenger to attend the conference, and when she heard that Bucky was being framed, she called Steve, and the first thing she said to him was, “I know how much Barnes means to you. I really do. Please, stay out of this. You’ll only make it worse” (40:52-41:05). Even Natasha knows that Steve would have acted irrationally in any situation regarding Bucky Barnes. For background, Nat and Steve have teamed up several times throughout the MCU and usually confide in one another, so they are very close.
Later on, the Civil War is less about the government issues against the Avengers and more about Tony not trusting Bucky and wanting to turn him in, while Steve spends the whole movie protecting Bucky. This is shown when Steve goes to Romania to make sure that the government does not get a hold of Bucky. When the two come face-to-face, the German special forces show up at his apartment, and Steve fights them off to let Bucky escape. He’s followed by the Black Panther, and once again, Steve goes against the German forces, another superhero, and Rhodey (who is a ranking officer in the U.S. Air Force). The first thing he says to Cap is “Congratulations, Cap. You’re a criminal now.” Steve became a criminal of the U.S., all because he wanted to keep Bucky (who hardly remembered him) safe.
Additionally, in this movie, Steve and Sam Wilson (Falcon and later the new Captain America) house Bucky in a secret location to keep him hidden from Tony and the government. When he first comes to, Steve and Sam question Bucky a lot. They do not have a lot of proof that Bucky remembers Steve because a lot of the things he is saying is put into the museum about Cap; however, Bucky mentions how Steve used to stuff old newspapers in his shoes, to which Steve looks at Sam and says, “You can’t read that in a museum.” To Steve, who knows all that Bucky went through with Hydra, any mention of something specific from their time as kids is proof enough that his Bucky is still there. He knows Bucky is going to come back to normal, and when he does, they will fight against the other Avengers with anyone else who is on Steve’s side.
My last point about this movie is regarding the information about the death of Tony’s parents. Steve had known the entire time and not once mentioned it to Tony because he knew things would be different between them. Steve knew it was Bucky who had killed them (while he was the Winter Soldier) and assumed Tony would react poorly, but he also did not want to tell anyone to protect his friend. You could quite literally say that the Civil War started because Steve cared more about protecting Bucky than literally anything else.
Going back to the “with you till the end of the line” motif, that is quite literally shown in every single Captain America movie (except for Avengers: Endgame). Steve went against the other half of the Avengers, searched for Bucky for years, went rogue for two years after the events of Civil War (after helping Bucky), broke into Hydra to find his friend, and spent his life thinking about how to fix the world. You’re telling me he did all this for one friend and then still made the decision to go and be with Peggy? This motif is literally so clear in every single Steve/Bucky scene, and the entire Captain America trilogy shows that he values his and Bucky’s friendship over everything.
The thing that does not fit Steve’s character is the fact that at the end of Endgame, he literally leaves all of his friends (SPECIFICALLY BUCKY) that he spent time protecting and caring for. The one thing that was consistent about every Captain America movie was that Steve Rogers was trying to save Bucky Barnes from every threat. Now you are going to tell me that he just decided to dip and marry a woman he had known for only a few months, who also had an entire life after Steve died. Not only did that completely swerve the repeating of “with you till the end of the line,” but it also just made Bucky a side character when he was something Steve fought for.
And I feel for Peggy, too. Not only was Steve’s choice one that will most likely mess with the timeline, but it also messes with Peggy’s story. In 2015, four years after Captain America: The First Avenger was released, there was a show called Agent Carter that followed the events of Peggy’s life after Steve was frozen in the water. We learn bits and pieces from her niece, Sharon, in the main storyline, but in the show, we learn that Peggy has had at least two relationships since Steve allegedly “died,” and that she also ended up with a husband and two kids. Theories have assumed that Steve Rogers has always been her husband, but in my opinion, I don’t think that is the case.
In The First Avenger, Peggy is a pretty independent person. She does not give in to the antics of the other soldiers and can hold her ground well. This makes me believe that Peggy would have the ability to move on from Steve and be able to build a life beyond him. Her character’s only thought was never about a man; she was compassionate, wanted to make a change, and was willing to risk anything to help others. She spent her life creating S.H.I.E.L.D. I just think that her storyline revolves around Steve too much, and I understand that the two of them were important to one another, but I do think she would have moved on. Steve going back in time kind of just ruined all the character development she was having. I like to think that Steve would have respected the life Peggy built and wanted her to be happy without him.
Also, I’m not saying that Steve does not deserve a happy ending. I think all the Avengers deserve one after everything they have been through and all they do for everyone else, but I do not think that Steve’s happy ending should come at the expense of screwing up the timeline. He deserves to be happy and live the rest of his life with joy (and I get that Peggy made him happy, but just listen), but he should have stayed in the present with everyone else. He picked the stones up and dropped them off on their planets and timelines, then created an entire new life. He deserves a happy ending that fits his character’s motivations, which have been to protect his friends and family (the Avengers).
I also think that this ending sort of ruined the idea that his character needed to learn to move on. In the first Avengers film, he holds on to all this confusion of the future while trying to understand what is at stake. As time progresses, he begins to understand the future and all that is going on around him, so why go and take that away? If he did not move on from Peggy, he would not have joined the Avengers and found Bucky as he does in every movie.
And obviously, Marvel has these different phases in the MCU, the newest one dealing with Dr. Doom (who is a Tony Stark variant), and clearly, Steve is now important in this film (or his kid is), but Steve’s ending before Avengers: Doomsday was announced, just somewhat wrote him out of the franchise.
After all of this, there is no way that Steve Rogers, who values his friendships above all else, decided to stop by and casually marry Peggy before going back to the normal timeline to see his friends. Steve Rogers always went back for Bucky. No matter the risk, the disagreements, or the issues it would create. Steve never stopped helping Bucky.