My parents, and grandparents were all born here, they all only spoke English, so minus those who can trace themselves back to th Mayflower I consider myself as American as they come- but most of my ancestors were Italian with a little German and a little Dutch mixed in on my Mom's side.
I have to go with BOP5 on this one... I was born & raised in the US (outside of Philly, Yo!) and as such I am 100% American like my parents before me. However, going back to my great-grandparents & their families, they come from England, Ireland, Poland, Germany, with some PA Dutch thrown in.
I was born in England but my family comes from Wales and Portugal but to top it off my paternal grandparents are from an area near Hull that has quite a bit of Nordic influence and my maternal grandparents probably have some mourish influence because of the mourish ocupation of the Iberian Peninsula.