Hanna v. Plumer

federal courts are obliged to apply state law in cases brought under diversity jurisdiction. The question in the instant case was whether Federal Rules of Civil Procedure governing service of process should yield to state rules governing the service of process in diversity cases. The Court ruled that under the facts of this case, federal courts shall apply the federal rule. The decision was drafted by John Hart Ely, who was then a law clerk for Earl Warren

automobile accident in South Carolina, allegedly caused by the negligence of one Louise Plumer Osgood, a Massachusetts citizen deceased at the time of the filing of the complaint. Respondent, Mrs. Osgood's executor and also a Massachusetts citizen, was named as defendant. The Massachusetts rule at the time required personal service of process on the executor of an in-state defendant, while Fed. R. Civ. P. 4 (d)(1) required only that service be made on a competent adult who resides at the residence of the defendant. The plaintiff left process at the residence of the executor, and so complied with the federal rule but not the state rule. The District Court granted summary judgment to the executor for the plaintiff's failure to make adequate service of process, ruling that the state rule applied based on the Supreme Court's prior precedents. The United States Court of Appeals for the First Circuit