"Twothreebreak" posted this at the AMC blogs for 'Mad Men':
Have you ever wondered where the Sterling Cooper offices were actually located, not just "Madison Avenue" but the actual address? Well, this screen grab of Roger in his office reveals that they were located just across the street from St. Patrick's Cathedral.
The only place this view is of the Cathedral and the GE Building (Rockafeller Center) is possible is on Madison Avenue's east side between 50th and 51st Streets. The problem is that the famous Villard Masion is located there and has been since 1882.
At only 6 stories tall it is impossible that this is where the Sterling Cooper offices were located (the building is supposed to have a 23rd floor as per dialogue).
So even if there is no real building where Sterling Cooper could have resided, it is kind of cool knowing that it was roughly 455 Madison Avenue between 50th and 51st Streets.
As with all other mentions of fictional geography from Toobworld, we always have to remember that this isn't the real world.....