In the United States v. Munson Steamship Line case in 1930, the Supreme Court dealt with a dispute over tariffs on imported goods. The Munson Steamship Line had been importing sugar from Cuba to Puerto Rico and was charged duties under the Tariff Act of 1922. They argued that since both countries were U.S territories, they should not be subjected to these charges. However, the government contended that Puerto Rico's status as an unincorporated territory made it subject to import duties like any foreign country would be. The court ruled in favor of the government stating that while Congress has broad powers over territories, it does not have unlimited power and cannot impose taxes or other burdens which violate constitutional rights of citizens residing there but can regulate commerce between them and states by imposing customs duties on goods shipped into one from another if such regulation is reasonably related to its powers over these possessions.

In the dissenting opinion for United States v. Munson Steamship Line, it was argued that the majority's decision to uphold a tax on foreign-built yachts violated principles of international law and comity. The dissent contended that such a tax constituted an improper interference with free trade and navigation rights, as well as an unjustifiable burden on foreign commerce. It further asserted that this taxation could potentially lead to retaliatory measures from other nations, thereby harming American interests abroad. Moreover, the dissent pointed out inconsistencies in how different types of vessels were taxed under U.S law; while domestic ships used for commercial purposes were exempted from taxes, foreign-built pleasure yachts were not given similar exemptions despite their non-commercial nature.