In The United States, Appellants v. Moses E. Levi, the Supreme Court was asked to decide whether a collector of customs in Savannah had authority to seize goods imported from foreign countries without payment of duties due on them under existing laws and regulations. The court held that the collector did have such authority and could lawfully make seizures for nonpayment of duties as required by law. In doing so, it affirmed an earlier decision by the Circuit Court for Georgia which found that a seizure made by the Collector was valid and lawful because he acted within his statutory powers when he seized certain merchandise belonging to Levi after it had been brought into port without paying duty on it as required by law. This ruling established that collectors are authorized to take action against those who violate federal revenue laws or regulations concerning importation of goods into ports in order to protect government revenues from being lost through illegal activities like smuggling or evasion of taxes or tariffs imposed upon imports entering US ports.

In the case of The United States v. Moses E. Levi, the Supreme Court was tasked with determining whether a federal court had jurisdiction to hear an appeal in a case involving land claims under Spanish law that were brought before it by citizens of Florida who had been granted title to certain lands by Spain prior to its cession of Florida to the United States. In this particular instance, Chief Justice Marshall wrote for the dissenting opinion and argued that while Congress has authority over territories acquired from foreign nations, they do not have absolute power over them and must respect any existing laws or rights held by individuals within those territories at the time of acquisition. He further stated that since these claimants already possessed valid titles under Spanish law when Florida was transferred to U.S., their right should be respected and upheld as if they were citizens of either country regardless which one actually holds sovereignty over them now; thus making it necessary for federal courts to exercise jurisdiction in such cases so long as there is no conflict between state and national laws on this matter.