In the case of La Nereyda, The Spanish Consul was the libellant. This Supreme Court case involved a dispute between two vessels over ownership and possession of a cargo ship called La Nereyda. The vessel had been captured by French privateers during the Napoleonic Wars and sold to an American citizen who then transferred it to another American citizen. After being seized by Spain in 1820, it was brought into port at Havana for adjudication as prize property of Spain. In this case, Chief Justice John Marshall held that under international law, title to enemy's property is not divested until after condemnation proceedings have taken place before a competent tribunal; thus, since no such proceedings took place prior to its seizure by Spain in 1820 or subsequent thereto up until the time when suit was instituted against her in U.S., she still retained title and right of possession over said vessel which must be respected by all other nations including United States itself despite any intervening transfers made with respect thereto while same remained within jurisdiction thereof .

In La Nereyda, the Spanish Consul brought a libel suit against an American vessel for taking on board and carrying away certain slaves from Cuba. The Supreme Court held that the act of transporting slaves was not illegal under international law or by treaty between Spain and America. However, Justice Johnson dissented in this opinion, arguing that slavery is contrary to natural justice and therefore should be prohibited by all nations regardless of any treaties or laws. He argued further that since it was well known at the time of ratification of the Treaty between Spain and America that slavery existed in both countries, it could not have been intended as part of their agreement to permit such acts as those committed here. Therefore he concluded that Congress had no authority to pass legislation permitting transportation of slaves from one country to another without violating its own Constitution which prohibits importation into any state after 1808.