United States v. Alexander was a United States Supreme Court case that dealt with the issue of whether a defendant could be convicted of a crime if the indictment was not found until after the statute of limitations had expired. The defendant, Alexander, was indicted for a crime that had occurred more than three years prior to the indictment. The Supreme Court held that the indictment was valid and that the defendant could be convicted of the crime. The Court reasoned that the statute of limitations was not a bar to prosecution, but rather a defense that the defendant could raise at trial. The Court noted that the statute of limitations was intended to protect defendants from having to defend themselves against stale charges, but that it did not prevent the government from bringing a valid indictment. The Court also noted that the statute of limitations was not a jurisdictional bar, and that the government could still bring a valid indictment even if the statute of limitations had expired. The Court's decision in United States v. Alexander established that the statute of limitations is a defense that can be raised at trial, and that the government can still bring a valid indictment even if the statute of limitations has expired. This decision has been cited in numerous cases since then, and has been used to support the idea that the statute of limitations is not a jurisdictional bar to prosecution.

In United States v. Alexander, the Supreme Court was asked to decide whether a federal court had jurisdiction over an indictment for murder committed on board of a vessel in navigable waters. The majority opinion held that the federal courts did have jurisdiction and affirmed the conviction of the defendant, William Alexander. However, Justice Field dissented from this decision arguing that Congress had not given any authority to punish crimes committed on vessels within navigable waters by individuals who were neither citizens nor residents of any state or territory. He argued that such power should be left with individual states as it has been since before adoption of the Constitution and would remain so unless specifically granted by Congress through legislation. Furthermore, he noted that if Congress intended to grant such powers they would have done so explicitly rather than leaving it up to interpretation by judicial decisions which could lead to potential abuse and usurpation of state sovereignty rights under our system of government