Full Faith and Credit

Article IV, Section 1 provides that full faith and credit shall be given in each state to the public acts, records, and judicial proceedings of every other state, and lets Congress prescribe how they are proved and what effect they have. The clause, carried over from the Articles of Confederation, was meant to turn independent states into a single nation in which a court judgment won in one state could be enforced in another. Congress passed the first implementing law in 1790, and the rule now appears in federal statute.

Courts apply the clause most strictly to final court judgments: a judgment validly entered in one state must generally be enforced in others, even if the second state would have decided the case differently. State laws receive more flexible treatment, and a state usually may apply its own law in its own courts. Divorce was an early battleground, and in Williams v. North Carolina in 1942 the Court required states to recognize out-of-state divorces granted to residents. Marriage, birth certificates, and adoptions have raised similar questions.

The Defense of Marriage Act of 1996 said states need not recognize same-sex marriages from other states, a provision made moot by Obergefell v. Hodges in 2015 and repealed by the Respect for Marriage Act of 2022. Since the 2022 Dobbs decision, states with opposite abortion laws have clashed, as some states passed shield laws barring cooperation with out-of-state prosecutions or lawsuits against their own providers, and in 2025 a New York county clerk declined to file a Texas judgment against a New York doctor. Courts may resolve how far the clause reaches in these disputes.