In the case of Ex Parte The Union Steamboat Company, 1899, the U.S. Supreme Court ruled on a dispute involving maritime law and jurisdiction. The Union Steamboat Company had been sued in a state court by an injured employee who sought damages for negligence under New York's Employer’s Liability Act. However, the company argued that federal maritime law should apply instead of state law because the injury occurred on navigable waters while unloading cargo from one of its steamboats docked in Buffalo, New York. The company petitioned to remove the case to federal court based on this argument but was denied by both lower courts. Upon appeal to the Supreme Court, it held that although general maritime law is indeed within exclusive federal jurisdiction as per Article III Section 2 of Constitution; Congress has also granted concurrent jurisdiction over certain cases (including personal injuries) to state courts through Judiciary Act of 1789. Therefore, even though plaintiff's claim could have been pursued under either federal or NY State laws due their overlapping jurisdictions over such matters; he chose latter which was his right and thus removal request was rightly denied - affirming decisions made by lower courts.

In the dissenting opinion for Ex Parte The Union Steamboat Company, 1899, it was argued that the majority's decision to deny a writ of habeas corpus and allow extradition proceedings against an individual accused of committing fraud in Canada was incorrect. The dissenting justices believed that the crime committed did not meet the criteria set out in existing treaties between Canada and America for extradition. They contended that these treaties only allowed extradition for crimes considered fraudulent under both American and Canadian law at the time they were committed. In this case, while what had been done might be seen as unethical or immoral by some standards, it wasn't technically illegal under either country's laws when it occurred. Therefore, according to their interpretation of international law principles regarding jurisdiction over criminal matters and treaty obligations between nations, they felt there should be no legal basis for extraditing someone from America to face charges in another country where no corresponding crime existed domestically at relevant times.