U.S. Supreme Court delivers its opinion in Erie Railroad Co. v. Tompkins and overturns a century of federal common law.

The Supreme Court of the United States (SCOTUS) is the highest court in the federal judiciary of the United States. It has ultimate appellate jurisdiction over all U.S. federal court cases, and over state court cases that turn on questions of U.S. constitutional or federal law. It also has original jurisdiction over a narrow range of cases, specifically "all Cases affecting Ambassadors, other public Ministers and Consuls, and those in which a State shall be Party". In 1803, the court asserted itself the power of judicial review, the ability to invalidate a statute for violating a provision of the Constitution. It is also able to strike down presidential directives for violating either the Constitution or statutory law.