United States v. Padelford was a United States Supreme Court case that dealt with the issue of whether the United States government had the right to seize goods from a vessel that was suspected of violating a federal law. The case arose when the United States government seized a vessel owned by Padelford, a merchant, for allegedly violating the Revenue Act of 1862. Padelford argued that the seizure was unconstitutional because it violated his Fourth Amendment right to be free from unreasonable searches and seizures. The Supreme Court held that the seizure was constitutional because the government had probable cause to believe that the vessel was violating the Revenue Act of 1862. The Court reasoned that the government had a legitimate interest in enforcing the law and that the seizure was necessary to prevent the vessel from continuing to violate the law. The Court also held that the seizure did not violate the Fourth Amendment because the government had probable cause to believe that the vessel was violating the law. In conclusion, the Supreme Court held that the seizure of Padelford's vessel was constitutional because the government had probable cause to believe that the vessel was violating the Revenue Act of 1862. The Court also held that the seizure did not violate the Fourth Amendment because the government had a legitimate interest in enforcing the law and that the seizure was necessary to prevent the vessel from continuing to violate the law.

In United States v. Padelford, the Supreme Court was tasked with determining whether a federal statute allowing for the seizure of goods illegally imported into the United States applied to goods that were brought in prior to its passage. The majority opinion held that it did not apply retroactively and thus could not be used against Padelford who had been charged with importing illegal merchandise before the law was passed. Justice Field dissented from this decision, arguing that Congress has always had authority over imports and exports since its inception under Article I of the Constitution and therefore should have been able to pass laws regulating them at any time without regard for when they occurred or how long ago they happened. He argued further that if Congress is allowed to regulate imports after their occurrence then it should also be allowed to punish those who violate such regulations regardless of when they took place as well; otherwise, criminals would go unpunished simply because their crime predated a particular law's enactment date.