Steve at the end of the film

TLDR: Old Steve has always been around, laying low and staying out of history's way.


So the Russos are saying old Steve came from an alternate timeline

But Markus & McFeely (the writers) are saying he's been in the same timeline all along

Arguably, the directors "own" the final product and their say-so overrules everyone else (although I still side with Harrison Ford over Ridley Scott on the Deckard/replicant issue).

But I'm starting to come around to the writers' viewpoint.

First, they were clearly keeping the question of Peggy's husband secret throughout all the films. The idea that he might be a time-traveling Steve was likely always in Feige's head.

Second, the big one, is why Steve would stand aside and let Hydra run Shield, let New York get trashed, let Ultron airlift Sokovia, etc. How could someone of his unshakeable principles just stand by?

But then I thought ... that's EXACTLY what someone of unshakeable principles would do ... IF HE KNEW IT'S WHAT HE'D ALREADY DONE.

In other words, Steve already knows that the timeline(s) must be preserved. That's why he's going to return all the stones himself. Once he then settles in 1940, he'd know that his first priority is to preserve the timeline, no matter how much he'd want to get involved. Presumably, Peggy would understand this as well.

One problem, where'd he get the shield he gave to Sam?

I supposed he could've brought it from an alternate timeline while returning the stones. If we take the Ancient One's words literally (and presume she's correct, which she hasn't always been), removing the stones creates alternate timelines. Removing a shield might not.

Certainly, there's no indication that Clint's son's missing baseball glove did any damage.

And of course it's also possible that Peggy, with her connections, got enough vibranium from, say, the ruins of Sokovia, to build a new shield. So when old Steve says it's Sam's shield, no one else's, he's being quite literal.