Cheek Wells was killed in a grinding-wheel accident in Alabama. The administratrix of Wells’s estate (plaintiff) filed a wrongful-death suit in federal district court in Pennsylvania against Simonds Abrasive Company (Simonds) (defendant), the Pennsylvania company that manufactured the grinding wheel. Alabama’s statute of limitations required a wrongful-death suit to be commenced within two years of the death. Pennsylvania’s statute of limitations required a suit to be commenced within one year of the death. Simonds moved for summary judgment, arguing that Pennsylvania’s statute of limitations applied to the action. The district court agreed and granted the motion. The court of appeals affirmed. The United States Supreme Court granted certiorari to review.