The United States versus La Vengeance was a Supreme Court case that centered around the issue of whether or not a French privateer, La Vengeance, could be considered an enemy vessel. The court ultimately ruled in favor of the United States and held that even though France had declared war against Britain at the time, it did not automatically make all vessels from France enemies to America. The court reasoned that since there was no formal declaration of war between America and France at the time, any acts committed by French vessels would have to be judged on their own merits as either hostile or friendly towards American interests. This decision set an important precedent for how future cases involving foreign ships should be handled in U.S courts.

In The United States v. La Vengeance, the Supreme Court was asked to decide whether a French vessel captured by an American privateer during the Quasi-War with France should be considered as a prize of war or returned to its original owners. Justice Samuel Chase wrote in dissent that he believed the capture of La Vengeance was illegal because it occurred after Congress had declared an end to hostilities between America and France. He argued that since there were no longer any acts of hostility taking place between the two countries, it would have been unlawful for an American privateer to seize a French ship at sea without first obtaining permission from either country's government. Furthermore, he contended that even if such permission had been granted, it could not have extended beyond what was necessary for self-defense against immediate danger; therefore, La Vengeance should be released and restored back into its rightful owner's possession without delay.