Swift v. Tyson

Swift v. Tyson
Supreme Court of the United States
Decided January 25, 1842
Full case name	John Swift v. George W. Tyson
Citations	41 U.S. 1 (more) 10 L. Ed. 865; 1842 U.S. LEXIS 345
Prior history	On a certificate of division from the Circuit Court of the United States for the Southern District of New York
Holding
Federal courts were to apply state statutory law, but not common law, to state cases.
Court membership
Case opinions
Majority	Story, joined by unanimous
Concur/dissent	Catron
Overruled by
Erie Railroad Co. v. Tompkins

Swift v. Tyson, 41 U.S. 1 (1842), was a case brought in diversity in the Circuit Court for the Southern District of New York on a bill of Exchange accepted in New York in which the Supreme Court of the United States determined that United States federal courts hearing cases brought under their diversity jurisdiction pursuant to the Judiciary Act of 1789 must apply the statutory law of the states when the state legislature of the state in question had spoken on the issue but did not have to apply the state's common law in those cases in which that state's legislature had not spoken on the issue. The Court's ruling meant that the federal courts, when deciding matters not specifically addressed by the state legislature, had the authority to develop a federal common law.

Judiciary Act of 1789, §34: "the laws of the several states, except where the constitution, treaties or statutes of the United States shall otherwise recognise or provide, shall be regarded as rules of decision in trials at common law, in the courts of the United States, in cases where they apply."

The Court: