In a brief interview with Edward Gross, Joe Johnston was quizzed on how Captain America might fit into the existing Marvel film universe.
Asked how other properties might tie into his take on the First Avenger, the same way Nick Fury cropped up in Iron Man and Thor’s hammer appeared in Iron Man 2, the director responded:
There are links between all the MARVEL films, mostly ones that only the fans will pick up on.
We have several subtle references to certain elements in THOR, but since CAPTAIN AMERICA is a period picture taking place in the 40’s, there are fewer opportunities for contemporary links to the rest of the MARVEL universe.
We can, however, create events in our story that will be paid off in AVENGERS and other MARVEL pictures.