I don't remember the name of it but looking at the current menu I think it was Old Stitch. If anyone has the chance to visit I highly recommend it for not just for the beer but for the history.
Old Stitch was one of the numerous 18th century slang terms for strong beer, along with names like Stingo and Dragons Milk. If they brewed the beer you had to anything to an 18th century recipe, it probably was a stock ale (a historical half-step between an IPA and an Imperial IPA, with a certain amount of overlap with modern old ales and the weaker English barleywines).
If you're still interested in historical beer recipes, a few years ago there was a rather nice historical porter recipe derived from Ben Franklin's porter recipe brewed in honor of his 300th birthday.
There are also scads of 18th and 19th century brewing manuals online using Google books search, as well as blogs devoted to historical beer research (e.g., http://barclayperkins.blogspot.com/