Spoilers ahead for Avengers: Endgame.
One of the more confusing aspects of Avengers: Endgame’s time travel trickery is the ending to Captain America’s story. At the end of the movie, Captain America (Chris Evans) goes to put the Infinity Stones back in time where they came from so as not to disrupt the timeline. But then he decides to stay in the 1940s with Peggy Carter (Hayley Atwell) and grow old with her. This raises the question: Did Cap’s presence in the past create a new timeline?
Screenwriters Christopher Markus and Stephen McFeely talked to Fandango about that ending for Steve Rogers and they think that it’s okay keeping him in the past:
So people are asking… Does this mean an old Captain America was hanging out this whole time while another Captain America was saving the day?
Christopher Markus: That is our theory. We are not experts on time travel, but the Ancient One specifically states that when you take an Infinity Stone out of a timeline it creates a new timeline. So Steve going back and just being there would not create a new timeline. So I reject the “Steve is in an alternate reality” theory.
I do believe that there is simply a period in world history from about ’48 to now where there are two Steve Rogers. And anyway, for a large chunk of that one of them is frozen in ice. So it’s not like they’d be running into each other.
I’m okay with that not being an alternate timeline. My question is what kind of person would Steve Rogers be in the past. He still had the gift of the Super Soldier serum, so would he commit himself to helping others? Would he have to get a new identity? Captain America was pretty famous during World War II, so how would he handle that? There are a bunch of logistical nitpicks, but I don’t really mind because it works thematically for the character.
What do you think about the ending of Captain America’s story? Did it work for you? Sound off in the comments.