The United States v. Hooe, et al., was a case heard before the Supreme Court of the United States in 1805. The case involved an indictment against Thomas and William Hooe for violating the Neutrality Act of 1794 by trading with French vessels during wartime. The defendants argued that they had not violated any laws because their actions were authorized by President John Adams' Proclamation of April 22, 1800 which declared that all trade between France and its colonies would be allowed under certain conditions. However, Chief Justice Marshall ruled that while Congress has authority to pass laws regulating foreign commerce, it is unconstitutional for them to delegate this power to the executive branch as Adams did in his proclamation. Therefore, he concluded that since there was no congressional authorization for such trading activities at the time when they occurred, Thomas and William Hooe's actions constituted a violation of federal law and thus were guilty as charged.

In the United States v. Hooe, et al., Chief Justice John Marshall delivered a dissenting opinion in which he argued that the Court should not have dismissed an indictment against two individuals for violating a federal law prohibiting trading with Native Americans without permission from Congress. He reasoned that since this was a criminal case, it was up to the jury to decide whether or not there had been any violation of the law and thus no grounds existed for dismissing the indictment on appeal. Furthermore, he noted that if Congress had intended to exempt certain persons from its prohibition then they would have done so explicitly in their legislation rather than leaving it open-ended as they did here. Finally, Marshall concluded by stating his belief that such exemptions could only be granted through legislative action and not judicial interpretation of existing laws.