In The United States v. The Brig Union, the Sloop Sally and Cargo, and the Sloop Deborah and Cargo, a case heard by the US Supreme Court in 1808, it was determined that vessels captured as prizes of war must be brought before a court to determine whether they are lawfully subject to capture. In this particular case two sloops were seized on suspicion of being engaged in illegal trade with French colonies during wartime. After an extensive investigation into their activities it was found that there was no evidence that either vessel had been involved in any unlawful activity or trading with France at all; therefore both ships were ordered released from custody without penalty or forfeiture. This ruling established precedent for future cases involving captures made during times of war: if there is not sufficient proof to support claims against a vessel then it should be released without consequence.

The dissenting opinion in The United States v. The Brig Union, the Sloop Sally and Cargo, and the Sloop Deborah and Cargo argued that Congress had not authorized a seizure of vessels for violating an embargo law. Chief Justice Marshall wrote that although it was true that Congress had prohibited certain trade with France, they did not authorize any seizures or forfeitures as punishment for violations of this prohibition. He also noted that even if such authority existed within the statute itself, it would be unconstitutional because only Congress has the power to declare war or impose penalties on citizens without trial by jury - both of which were necessary components of forfeiture proceedings at common law. Finally, he argued that since no penalty was specified in the act itself nor could one be implied from its language then there was no legal basis upon which to seize these vessels or their cargo.