Swift v. Tyson

Case Date: 05/23/2019

Swift v. Tyson, 41 U.S. 1 (1842)[1], 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.