Facts of the Case

Tompkins brought a lawsuit in federal court in New York against the Erie Railroad for personal injuries. Tompkins had been walking along the railroad tracks in Pennsylvania when he was hit by an open railcar door. Under Pennsylvania law, where the accident occurred, the railroad owed no duty to Tompkins. But this was the "law" according to the Pennsylvania courts. There was no statute of the state legislature declaring the law. In the federal courts, the railroad had a duty to take care. A federal court jury awarded Tompkins damages. The verdict was upheld on appeal.

Question

Does the law of the several states applied by the federal courts as rules of decision in civil cases include all the decisional or common law of the states?

Conclusion

In 1842, the Supreme Court held that the laws of the several states embraces only the statutes authored by the state legislatures. Federal judges were free to ignore the states' common (judge-made) law and substitute their own rules. Brandeis rejected this long-standing precedent on several grounds including the view that the 1842 decision represented "an unconstitutional assumption of power by the Courts of the United States." This case was a grand victory for states to express public policy through the decisions of state courts without interference from federal judges.