Both sets of my grandparents came to the U.S. from Europe (France and Belgium) just before WW II. They did not become citizens. My father and mother were born in the U.S. and lived here all their lives. I was born in the U.S. and have also lived here all of my life.

Am I a U.S. citizen? If so, what proof can I provide that doesn't rely on the "loophole"?