@darth-azrael
Cap traveled back to the year 1940, probably after he was frozen in the ice, and get from there on old. This means that there were 2 Captain Americas in the timeline. Then, when he got old, he traveled from the timeline where he got old to the main timeline to then hand over the shield. That's what I wanted to explain in the last part of this series. I've already finished it as raw and i will work it out a bit, altogether it will be with this 4 articles about the time travel case.