In The United States, Appellants v. The Heirs of Louis Boisdore, the Supreme Court was asked to decide whether a French citizen who had been living in Louisiana before it became part of the United States could claim ownership over certain land that he had acquired from Spain while it still held sovereignty over the area. At issue was whether or not Spanish law applied to this transaction and if so, did it grant Boisdore any rights under U.S. law? Ultimately, the court found that Spanish laws were applicable and granted Boisdore's heirs title to their property as they would have been entitled under those laws at the time of purchase. This decision established an important precedent for future cases involving foreign citizens' claims on lands within newly formed states or territories which had previously belonged to another country with different legal systems in place prior to annexation by America

In the case of The United States v. The Heirs of Louis Boisdore, the Supreme Court was tasked with determining whether a French citizen who had died in 1803 still held title to land he owned in Louisiana. At issue was whether or not his heirs were entitled to compensation for their loss when the U.S. government took possession of it after purchasing Louisiana from France in 1803 and subsequently selling it off as public lands without compensating them for their losses. In a dissenting opinion, Justice McLean argued that although there is no dispute that Boisdore's property rights were extinguished by virtue of the purchase agreement between France and America, his heirs should have been compensated under international law since they did not voluntarily relinquish ownership over their inherited land but instead lost it due to an act beyond their control – namely, the sale by America which occurred without any notice or consent on behalf of Boisdore's heirs. Therefore, Justice McLean concluded that these individuals deserved just compensation for this involuntary taking and should be granted restitution accordingly