Avengers Endgame ending majorly focused on Captain America. With him going toe to toe with Thanos and wielding Mjolnir, Endgame was more of an ending to the story arcs of Tony Stark and Steve Rogers.
The movie contains lots of quantum physics and different sets of rules for time-travel. Back to the Future is not canon at all. Many fans are confused over what happened at the end with Captain America. How did he turn old in just 2 minutes, after all? Here is the Avengers Endgame ending explanation from the directors.
Avengers Endgame Ending: Old Man Rogers Explained
At the end of Avengers Endgame, after Thanos is defeated, Captain America goes back in time to give back all the Infinity Stones to their original places. As explained by Dr. Bruce Banner and the Ancient One, an alternate timeline results from the removal of Infinity Stones. To prevent that, Infinity Stoners are to be returned at the exact place and exact time.
Steve Rogers a.k.a. Captain America easily returned all the Infinity stones to their respective owners. What an extraordinary effort to preserve the reality of all those timelines! Once done, he goes back in time to dance with his love Peggy Carter from The First Avenger. Steve lives a happy married life with her and gets old. He returns to 2023 as an old man to meet Banner, Bucky, and Sam. During the end scene of Avengers Endgame, he passes his shield and torch of Captain America to Sam Wilson a.k.a. Falcon.
Avengers Endgame Ending- Why no Alternate Timeline?
An alternate timeline is only created due to a void left by an Infinity Stone. But since Steve returned all of them, the timeline remained intact. When he met Peggy, he told her to keep it a secret. Captain America from future marries the past Peggy Carter while living in shadows and the events unfold as usual.
In Winter Soldier, when Peggy is talking about her husband, she is actually telling about Old Man Rogers who lived a normal life.
This clears all the Captain America timeline confusion and solves all our doubts. Stay tuned to Hiptoro for more Avengers Endgame updates and other news.