The U.S. Supreme Court case Fitzpatrick v. United States in 1899 revolved around the issue of whether a defendant could be tried for murder on an American ship, even if the crime occurred while the vessel was in foreign waters. The defendant, Mr. Fitzpatrick, had been convicted of murdering another crew member aboard an American vessel off the coast of Japan and appealed his conviction arguing that U.S courts did not have jurisdiction over crimes committed outside territorial limits. However, upon review by the Supreme Court it was determined that under international law and maritime law principles - which allow nations to exercise criminal jurisdiction over their own vessels regardless of where they are located - Fitzpatrick's trial and subsequent conviction were indeed valid within US legal framework. Therefore, despite being committed in international waters or foreign territory per se; such acts can still fall under US judicial purview provided they occur on board its national vessels (ships). This ruling thus affirmed federal courts' authority to try cases involving serious offenses like murder occurring on American ships irrespective of their geographical location at time of incident.

In the dissenting opinion for Fitzpatrick v. United States, Justice Harlan argued that the court majority had erred in its interpretation of the Constitution's provisions regarding impeachment trials. He contended that these proceedings are not judicial in nature but rather political, and therefore do not fall under the purview of Article III courts or require adherence to typical rules of evidence and procedure. Furthermore, he asserted that impeachments are intended as a check on public officials' abuse of power rather than as criminal prosecutions; thus, they should be conducted by Congress alone without interference from other branches of government. In his view, allowing an appeal to a federal court undermines this constitutional design by giving judges undue influence over impeachment outcomes.