Insect and Spider Identification: CLOSED: Is this a Swallowtail Butterfly? Missing Hindwing bottoms, 0 by greenbunny

greenbunny wrote:
I found this beautiful butterfly sucking up the nectar out of my two-year-old Purple Giant Hyssop here in Minneapolis, MN, but I can't tell what kind it is!

I didn't think to measure it, but I guarantee it was at least 6, if not 7 inches across (because it was larger than my hand from pinkie to thumb outstretched, and he/she hung around for a while). I've got a butterfly ID book, but this doesn't match anything I'm finding perfectly. What kind is it?

The body is yellow.

Thanks for your help!
Peace,
Carrie Anne