28 U.S.C. § 1251: Original jurisdiction

(a) The Supreme Court shall have original and exclusive jurisdiction of all controversies between two or more States. (b) The Supreme Court shall have original but not exclusive jurisdiction of:(1) All actions or proceedings to which ambassadors, other public ministers, consuls, or vice consuls of foreign states are parties; (2) All controversies between the United States and a State; (3) All actions or proceedings by a State against the citizens of another State or against aliens.