Conceived in an era when the right of individuals to change their citizenship was not universally recognized, the Bancroft treaties represented an important step forward in securing recognition by foreign governments of the right of their nationals to become American citizens. But American
constitutional law eventually made the treaties obsolete. In
Schneider v. Rusk, 377 U.S. 163 (1964), the
Supreme Court invalidated a section of the
Immigration and Nationality Act of 1952 (the McCarran-Walter Act) that would strip naturalized Americans of their citizenship after
three years' continuous residence in their country of origin; and in
Afroyim v. Rusk, 387 U.S. 253 (1967), the Supreme Court, reviewing part of the Nationality Act of 1940, held that
Congress has no power to strip anyone of their citizenship, whether it is acquired by birth or by naturalization. These decisions strongly suggested that any future case of involuntary loss of citizenship under one of the Bancroft treaties probably would not survive a Supreme Court challenge. ==Termination of the Bancroft treaties==