Jon Favreau has confirmed with MTV News that the character Howard Stark, father of "Iron Man" Tony Stark, will appear in Joe Johnston’s "Captain America: The First Avenger".
"Mad Men" star John Slattery plays Howard Stark in "Iron Man 2", a character who appears via a 1970's Stark Expo presentation video shot on a film reel that Nick Fury gives to Tony. A younger version of the character is expected to appear during the WW2 sequences in 'America'.
“Yeah, because he was around then. ['Captain America'] is World War II. It wouldn’t be that same actor, probably, because he would be much younger.[Howard Stark] was starting out during that time, and [he] was involved with the war effort, much like Howard Hughes” says Favreau.
A half-assembled version of Captain America's shield lies sitting in Tony Stark's workshop in "Iron Man 2" and is used at one point in the film to prop up an important experiment.