Cherokee Nation v. Georgia, 20 U.S. 1 (1831) – the Court held that tribes are not
foreign states, as that term is used in the Constitution, in describing the court’s
original jurisdiction over “controversies” between a state (here, the state of Georgia)
and “foreign states.” Rather, Justice Marshall’s opinion holds that tribes are
“domestic dependent nations,” whose relations with the U.S. resemble that of a “ward
to his guardian.” Marshall’s language represents the genesis of the trust doctrine in
federal Indian law, which holds that the U.S. has a trust responsibility to act on behalf
of Indian Tribes.