By Eileen M. Martin and Elizabeth M. Klarin ( June 11, 2026, 12:55 PM EDT) -- The United States constitution defines a U.S. citizen as any individual who is a citizen of the United States by law, birth or naturalization. But this isn’t always as clear as it may seem, as some individuals — particularly those born abroad to one or more U.S. citizen parents — may or may not be considered a U.S. citizen, sometimes without even knowing it....