Marcelin Haydel brought a case against Francois Dufresne to the Supreme Court of Louisiana. The dispute was over an alleged contract between them for the sale of certain slaves and their children, which Haydel claimed he had fulfilled but that Dufresne refused to pay him for. The lower court found in favor of Dufresne on the grounds that there was no written agreement between them, as required by law at the time. On appeal, however, the Supreme Court reversed this decision and held that verbal agreements were valid under Louisiana law if they could be proven through other evidence such as witnesses or documents related to it. This ruling established precedent in Louisiana regarding contracts made without writing and set a standard for future cases involving similar issues.

In the case of Marcelin Haydel v. Francois Dufresne, the Supreme Court was tasked with determining whether a contract between two parties could be enforced when it had been made in Louisiana before it became part of the United States. The majority opinion held that since Louisiana was not yet a state at the time of contracting, no valid contract existed and thus could not be enforced by U.S. courts. In his dissenting opinion, Justice Daniel argued that although Louisiana may have been under Spanish rule at the time of contracting, both parties were citizens or subjects to Spain and therefore should still be bound by their agreement according to Spanish law which recognized such contracts as binding obligations even after cession to another government entity like the United States. He further stated that if this principle is accepted then all other contracts entered into prior to cession would also remain enforceable regardless of any change in sovereignty over an area or region