The U.S. Supreme Court case "The J.P. Donaldson" in 1896 revolved around a dispute over maritime law and salvage rights. The steamship J.P. Donaldson had run aground near the coast of North Carolina, after which the crew abandoned it due to severe weather conditions. A group of salvors then arrived at the scene and managed to save part of its cargo before another storm hit, causing further damage to the ship and its remaining cargo. When taken to court, there was disagreement over how much compensation should be awarded for their efforts - with one party arguing that they were entitled to full value as per traditional salvage laws while others argued that this would be unfair given they hadn't saved everything on board or prevented further damage from occurring.

In the dissenting opinion for THE J. P. DONALDSON, 1896 case, Justice Harlan argued that the majority's decision was inconsistent with established principles of maritime law and international comity. He contended that a ship at sea should be considered an extension of its home country's territory and thus subject to its laws, regardless of where it is located when a crime occurs on board. In this case, he believed that the American courts had jurisdiction over crimes committed on an American vessel in international waters or foreign ports because they were essentially extensions of U.S soil. The majority’s ruling would mean any crime committed aboard could go unpunished if it occurred outside territorial waters - which he deemed unacceptable as it contradicted basic principles of justice and sovereignty.