In the United States v. Jonah Crosby, the Supreme Court was tasked with determining whether a federal statute that prohibited trading in goods between citizens of the United States and those of an enemy nation applied to individuals who had traded prior to its enactment. The defendant argued that he should not be held liable for his actions since they occurred before Congress passed this law. However, Chief Justice Marshall wrote for a unanimous court that it did apply retroactively because there was no language in the statute indicating otherwise and thus affirmed Crosby’s conviction. This decision established precedent regarding how statutes are interpreted when considering their application retrospectively or prospectively; if nothing is stated either way then courts will assume them to have been intended as retrospective laws unless there is clear evidence suggesting otherwise.

In the case of United States v. Jonah Crosby, the Supreme Court was tasked with determining whether a federal court had jurisdiction to try an individual for violating a state law. The majority opinion held that it did not have such authority and dismissed the indictment against Crosby. Justice Johnson dissented from this decision, arguing that Congress had granted federal courts power to hear cases involving violations of state laws in certain circumstances. He argued that since this particular case involved charges related to maritime matters, which are traditionally within the scope of federal jurisdiction, then it should be heard by a federal court rather than one established under state law. Furthermore, he noted that if Congress intended otherwise they would have explicitly stated so when granting these powers to lower courts in their legislation. Ultimately Johnson concluded that there was no reason why this matter could not be tried before a competent tribunal established by Congress and thus he disagreed with his colleagues' ruling on jurisdictional grounds