In suits arising from diversity citizenship, the Supreme Court held that federal courts were free to exercise an independent judgment in principles of general commercial law, even if the principles were inconsistent with decisions of state courts.
Section 34 of the Judiciary Act of 1789
By a 9-0 vote, the Supreme Court supported the plaintiff. Speaking for the Court, Justice Joseph Story
Common law, federal
Erie Railroad Co. v. Tompkins
Federalism
Judiciary Act of 1789