United States v. Pugh was a United States Supreme Court case that dealt with the issue of whether a defendant could be convicted of a crime if the indictment failed to allege the essential elements of the offense. The defendant, Pugh, was indicted for the crime of receiving stolen goods, but the indictment failed to allege that the goods were stolen. The Supreme Court held that the indictment was insufficient and that Pugh could not be convicted of the crime. The Court reasoned that an indictment must contain all the essential elements of the offense in order to be valid. The Court noted that the indictment in this case failed to allege that the goods were stolen, which was an essential element of the crime. Therefore, the Court held that the indictment was insufficient and that Pugh could not be convicted of the crime. The Court's decision in this case established the principle that an indictment must contain all the essential elements of the offense in order to be valid. This principle has been applied in numerous cases since then, and it is an important part of criminal law in the United States.

In United States v. Pugh, the Supreme Court was asked to decide whether a federal statute that allowed for the forfeiture of goods imported in violation of law applied to goods seized by customs officers before they were released from custody and delivered to their owner. The majority opinion held that the statute did apply, but Justice Field dissented on two grounds: first, he argued that Congress had not intended for such forfeitures; second, he argued that if it had been so intended then it would be unconstitutional as an ex post facto law. He reasoned that since no crime or offense had occurred prior to seizure and delivery of the goods there could be no forfeiture under this particular statute because it only applied when a person has committed some act which is punishable by forfeiture after conviction. Therefore, Justice Field concluded that allowing such forfeitures would constitute an ex post facto punishment prohibited by both state and federal constitutions.