re: Why do so many southern areas refer to themselves as americans on ancestry surveys?

My ancestors (of only one line) immigrated from England to America about 300 years ago. About 700 years before that they went from Normandy to England when William invaded and conquered the country. Before that who knows where they came from. There are some rumors that they were Roman settlers in the north of modern day France. I'm sure along the way they mixed with all kinds of different "ancestry."

At what point does trying to claim ancestry from a single place become completely meaningless? Because trying to claim my ancestry as being English seems completely meaningless to me. Maybe I claim Scotch-Irish because that's what my ancestors probably mixed the most with spending most of the last 300 years in the American South? I don't know. That seems pretty meaningless too. I'm American.