Kennedy Center American College Theatre Festival
It's a national theatre conference that's divided up into Regions. Usually held in January. Region II, also called the Chesapeake Region is comprised of PA, NJ, DE, MD, NY, and DC.
http://www.kcactf.org/Arielle - I was in region II in college and went to 4 festivals, though I never went with a full production. Let me know if there are any general questions that you have. Philly is my hometown, so I have plenty of suggestions about what to do and where to go!