I don't have a butterfly book nor have I been able to find this exact butterfly using google, but it does look a lot like a White Admiral. The Admiral has a thicker inner white band and maybe not as much blue. There's also the Poplar Admiral. Anyone know for sure?

Update: poking around some more I'm starting to think it's a Swallowtail, notably the Spicebush Swallowtail. Still unsure, but man what a crazy looking caterpillar stage!