After private plaintiffs brought suit against private defendants in the District Court to quiet title to certain land riparian to the Mississippi River, Louisiana intervened in the action and filed a third-party complaint against Mississippi seeking to determine the boundary between the two States in the vicinity of the disputed land. Following this Courts denial of leave to Louisiana to file a bill of complaint against Mississippi in this Court, the District Court found the land in question to be part of Mississippi and quieted title in the plaintiffs. The Court of Appeals reversed.

Held:

The uncompromising language of 28 U.S.C. 1251(a), which gives to this Court "original and exclusive jurisdiction of all controversies between two or more States" (emphasis added), deprived the District Court of jurisdiction over Louisianas third-party complaint against Mississippi. Though 1251(a) is phrased in terms of a grant of jurisdiction to this Court, the plain meaning of "exclusive" necessarily denies jurisdiction of such cases to any other federal