John McDonogh, plaintiff in error, brought a case against Laurent Millaudon and others. The dispute was over the ownership of certain real estate located in New Orleans. McDonogh argued that he had purchased the property from one of his creditors who held a valid title to it; however, Millaudon claimed that he owned the land by virtue of an earlier grant from Spain. The Supreme Court ruled in favor of McDonogh on two grounds: firstly, because Spanish grants were not recognized as valid titles under American law; and secondly, because even if they were considered valid titles at some point during this period, they became invalid when Louisiana was ceded to the United States by France in 1803. Furthermore, since no other party could prove their right to possess or use this land prior to its sale by McDonough's creditor - which occurred after 1803 - then it must be assumed that all rights belonged exclusively to him as purchaser with good faith and without notice of any defect or claim adverse thereto.

In John McDonogh v. Laurent Millaudon and Others, the Supreme Court was tasked with deciding whether a Louisiana state court had jurisdiction over an action brought by a non-resident of the state against two residents of Louisiana. The majority opinion held that it did not have such jurisdiction, as there were no sufficient contacts between the parties to establish personal jurisdiction in the case. However, Justice Catron dissented from this decision on grounds that he believed that due process required some form of minimum contact for any suit involving non-residents to be heard in a particular forum. He argued that since both parties resided within Louisiana at one point or another during their dispute, they should have been able to bring their claims before its courts regardless of where either party currently lived. Furthermore, he asserted that if states could not exercise personal jurisdiction over out-of-state defendants who had previously engaged in activities within their borders then those individuals would be allowed to escape liability for wrongs committed while inside them without consequence; something which would undermine public order and justice throughout America's judicial system as whole.