The Eleventh Amendment
Ratified in 1795, the Eleventh Amendment bars federal courts from hearing suits brought against a state by citizens of another state or of a foreign country. It is the textual foundation of modern state sovereign immunity doctrine.
The Eleventh Amendment was the first constitutional amendment ratified after the Bill of Rights, and it was a direct rebuke of a Supreme Court decision. In Chisholm v. Georgia in 1793, the Court held that a citizen of South Carolina could sue the State of Georgia in federal court to collect a Revolutionary War debt. The decision provoked outrage. States had assumed that their pre-constitutional sovereign immunity remained intact, and a flood of similar suits threatened to bankrupt several governments. Congress proposed the Eleventh Amendment within weeks. It was ratified in 1795.
The text is narrow: "The Judicial power of the United States shall not be construed to extend to any suit in law or equity, commenced or prosecuted against one of the United States by Citizens of another State, or by Citizens or Subjects of any Foreign State." Read literally, the amendment bars only suits against states by out-of-state or foreign citizens. The Supreme Court has read it more broadly. In Hans v. Louisiana in 1890, the Court held that the amendment also bars suits against a state by its own citizens, reasoning that the deeper principle was state sovereign immunity rather than the specific text of the amendment.
The doctrine has become a substantial limit on federal litigation against state governments. A private party generally cannot sue a state in federal court for damages without the state's consent, even to enforce federal law. Several escape valves exist. Congress can abrogate state sovereign immunity under its Fourteenth Amendment enforcement power. The federal government itself may sue a state. Suits against state officials in their official capacity for prospective injunctive relief are permitted under the fiction established by Ex parte Young in 1908. The basic principle remains. The states, as sovereigns, retain a substantial immunity from suit that predates and constrains the federal judicial power.