Most definitely the early 60s and not so much a wardrobe bleed-over as the fact that what we think of as "the 60s" (hippies, flower power, tye-dye, and a whole lot of hair) was actually pretty much just the 2nd half of the decade. Don't believe me? Watch real-life footage from the early 60s and see the fashions Mad Men recreated so accurately. I recommend watching the audience in Beatles concert footage circa 1963. It demonstrates my point and it's pretty entertaining besides. By the way, Kennedy was assassinated in late 1963 so yea, I'd say it was the 60s.

@ladykatza
The first season of Mad Men takes place in 1961.  They're very specific about the year in the context of the actual show.  (Last season ended with the Kennedy assassination - pretty sure that's the 60s.)

However, it's understandable that there'd be some fashion "bleed-over" from the 50s to the 60s.  You've still got clothes from 2008, right?  A new decade doesn't always mean a completely new wardrobe for everyone on the planet.

MadMen is definetly based in the early 60's.

Um,  Madmen is the 50's.  The sixties is a bit different.  Still, very nice outfit.

I follow What I Wore on my reader and I absolutely love it! 
I think the show is great and it is the perfect complement to Jessica's blog posts.

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