"Article IV, section 1, of the Constitution 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 the Congress may by general Laws prescribe the Manner in which such Acts, Records and Proceedings shall be proved, and the Effect thereof." This provision was designed to unify the nation by binding together its several states.
Dispute exists as to whether, as an original matter, the clause was intended to provide merely that public records, including judgments, could be admitted into evidence in other states, or whether it was intended to give such records conclusive legal effect in other states. The Constitutional Convention did not resolve this issue. Congress soon clarified matters by legislation, however. In 1790, it enacted a statute providing for the manner in which acts of legislatures and records of judicial proceedings of the states would be authenticated. In addition, Congress provided that "the said records and judicial proceedings shall have such faith and credit given to them in every court of the United States, as they have by law or usage in the courts of the State from whence the said records are or shall be taken." In 1804, Congress enacted another statute requiring that full faith and credit be given to the records and judicial proceedings of the territories of the United States.
The Supreme Court held in Mills v. Duryee (1813) and Hampton v. McConnell (1818) that a judgment rendered in one state or territory generally has conclusive effect in other states or territories. The court in the original state must have had jurisdiction, and the requirements of due process must have been satisfied. Also, the original judgment must have been on the merits and it must have been final. When there have been inconsistent judgments in other states, the last‐in‐time rule provides that the latest judgment gets full faith and credit.
The constitutional provision does not specifically address the recognition of state court judgments in federal courts or federal court judgments in state courts. But the Supreme Court held in Stoll v. Gottlieb (1938) and St. John v. Wisconsin Employment Relations Board (1951) that federal courts must grant full faith and credit to state court judgments, and vice versa.
Courts distinguish between the recognition of judgments under the Full Faith and Credit Clause and the enforcement of judgments. The method of enforcing a judgment must be determined under the law of the state where enforcement is sought. Moreover, the Full Faith and Credit Clause does not apply to the judgments of foreign countries, which are governed by principles of comity (Hilton v. Guyot, 1895).
The clause speaks not only of judgments and records, but also public acts, or statutes. The 1790 act however, spoke only of judgments and records, presumably because it would be difficult to establish general principles about when one state should be compelled to apply another's law. In 1948, Congress revised Title 28 of the United States Code, which contains the full faith and credit legislation, requiring that full faith and credit be given not only to records and judgments but also to acts. The exact scope of this provision remains in doubt, as courts have not construed it definitively. "