The Brigantine Amiable Lucy was a case heard before the United States Supreme Court in 1810. The case involved a dispute between the owners of the brigantine, who were Spanish citizens, and the United States government over whether or not they had to pay duties on goods imported into New York from Spain. The court held that since Spain and America had signed a treaty which exempted American vessels from paying duties when importing goods from Spain, then this exemption should also apply to foreign-owned vessels such as those owned by Spaniards. Therefore, it ruled that no duty should be paid for imports made by these vessels. This ruling established an important precedent regarding how treaties are interpreted under U.S law and has been cited in many subsequent cases involving international trade disputes between countries with similar agreements in place.

In The Brigantine Amiable Lucy v. The United States, Chief Justice Marshall wrote the dissenting opinion for the case. He argued that a vessel captured by an enemy and then recaptured by a neutral power should be restored to its original owners without any deduction of salvage or compensation for damages sustained during capture. Marshall reasoned that since no one was responsible for the damage done to the vessel while it was in possession of an enemy, no one could justly claim indemnity from those who had recovered it from them; therefore, he concluded that all rights which existed before capture must remain after recapture unless otherwise provided by treaty or act of Congress. Furthermore, he noted that if such deductions were allowed as proposed in this case, they would amount to nothing less than confiscation and forfeiture on behalf of private individuals rather than public authority - something which is not authorized under US law nor consistent with justice and equity principles.