While temporarily in New York, Larsen (plaintiff), a Danish seaman, signed documents to join the crew of the Randa, a Danish ship. The Randa was owned by Lauritzen (defendant), a Danish citizen. The documents that Larsen signed provided that any injury sustained aboard would be governed by Danish law as well as Lauritzen’s contract with the Danish Seamen’s Union, of which Larsen was a member. While the Randa was in Cuban waters, Larsen was injured aboard. Larsen filed suit in federal district court in New York under the Jones Act, a United States law that protected seamen who suffer personal injury during a voyage. Lauritzen argued that Larsen had already received all compensation available under Danish law. Larsen argued that Lauritzen’s business with the United States served as a legitimate basis for the court’s jurisdiction over the dispute. The district court agreed and issued a judgment against Lauritzen. Lauritzen appealed. The court of appeals affirmed. The United States Supreme Court granted certiorari to review.