Hugh Boyle, plaintiff in error, brought a case against James W. Zacharie and Samuel H. Turner to the Supreme Court of the United States. The dispute was over an agreement between Boyle and Zacharie for the sale of land located in Louisiana Territory which had been ceded by France to Spain before being purchased by the United States from France under the Louisiana Purchase Treaty of 1803. According to Boyle's claim, he had agreed with Zacharie that if he paid $2,000 within two years then title would be transferred to him; however when it came time for payment, Zacharie refused on grounds that his title was invalid due to Spanish laws still governing at time of purchase. The Supreme Court ultimately ruled in favor of Boyle as they found that since there were no valid Spanish laws applicable at time of purchase or transfer then any contract made prior should remain binding regardless if it violated those same laws post-purchase or not.

In the case of Hugh Boyle v. James W. Zacharie and Samuel H. Turner, Justice McLean delivered a dissenting opinion in which he argued that the plaintiff had not been given due process under the law as it was written at the time of trial. He believed that there were errors made by both parties during proceedings, but felt that these mistakes should have been corrected before judgment was rendered against Boyle; instead, they were allowed to stand without any consideration for their effect on his rights or interests. Furthermore, McLean argued that even if all procedural errors had been avoided, there still would have been an issue with how damages were calculated since no evidence was presented to support them and thus could not be considered valid or reliable enough to form a basis for such an award. Ultimately, he concluded that this decision violated Boyle's right to fair treatment under the law and should therefore be overturned on appeal so as to ensure justice is served in future cases like this one going forward