Board Thread:Episode Discussion/@comment-112155-20160203033421/@comment-1894786-20160207233143

GliderMan wrote: Council of Nine being connected to Hydra would be completely appropriate for this series. I know we're all a little burned out on them from Agents of SHIELD, but this is a spin off of The First Avenger, and we know Hydra has been inside SHIELD since the very beginning.

I reckon SHIELD will probably begin to form in 1949, when Operation Paperclip was enacted. Could always be earlier though. We know from the one-shot that Peggy and Howard headed SHIELD in '47. Until a third season set in 1948 proves us wrong, that's still canon. She worked for both until 1949. I don't know what the source for that is, but it's on her Wikia page, so I'll assume it's accurate.

So SHIELD existed since at least 1947.