In the 1902 case Downs v. United States, the Supreme Court ruled on a matter concerning import duties and tariff classifications. The plaintiff, Mr. Downs, imported goat skins from Mexico into El Paso, Texas and was charged with an import duty under a provision of the Tariff Act of 1897 that applied to "hides." Disagreeing with this classification, he argued that his goods should have been classified as "skins," which would have resulted in lower duties. He sued for recovery of what he believed were excessive charges. The Supreme Court sided with Mr. Downs' argument by interpreting the language used in previous versions of tariff laws and examining Congress's intent when it enacted those laws; they concluded that lawmakers had intended to distinguish between hides (which are thicker) and skins (which are thinner). Therefore, since goatskins fall into the latter category due to their thinness compared to other animal hides like cowhide or horsehide - they should be subject only to duties applicable for 'skins'. This ruling set precedent for future cases involving interpretation of tariff law.

In the dissenting opinion for Downs v. United States, Justice Harlan argued that the majority's interpretation of the Guano Islands Act was incorrect. He believed that Congress intended to extend U.S. sovereignty over guano islands and not just exercise jurisdiction there. In his view, this would mean that crimes committed on these islands should be tried under federal law as if they occurred within U.S territory rather than being subject to maritime law as decided by the majority ruling. Furthermore, he disagreed with their assertion that a ship anchored at a guano island is still considered in transit on high seas; instead arguing it should be treated as within U.S territorial waters due to its location and purpose of visit (collecting guano). Thus, he concluded that Downs' conviction for murder should stand because it happened on what he considers American soil - contrary to the majority who overturned it based on technicalities about where exactly crime took place.