In United States v. Dashiel, the Supreme Court of the United States held that a person who had been convicted of an offense in one state could not be tried again for the same offense in another state. The case involved a man named John Dashiel, who was charged with larceny and burglary in New York State. He was found guilty and sentenced to five years' imprisonment. After his release from prison, he moved to Pennsylvania where he was arrested on similar charges based on evidence obtained from witnesses at his original trial in New York State. The Supreme Court held that this violated the Double Jeopardy Clause of the Fifth Amendment which prohibits any person from being "twice put in jeopardy" for "the same offence." As such, it reversed Dashiel's conviction and ordered him discharged from custody without prejudice to further prosecution by either state or federal authorities if they so chose.

In United States v. Dashiel, the Supreme Court was tasked with determining whether a federal statute that imposed an additional duty on goods imported from foreign countries into the United States applied to goods already in transit when the law went into effect. The majority opinion held that it did apply and affirmed the lower court's decision. However, Justice Field dissented, arguing that Congress had no authority to impose such duties retroactively as doing so would violate due process of law under Article I Section 9 of the Constitution which states "No Bill of Attainder or ex post facto Law shall be passed." He argued further that if Congress could pass laws imposing taxes retroactively then they could also pass laws punishing individuals for past actions without trial by jury or other constitutional protections afforded by criminal proceedings. Therefore he concluded that this particular statute should not be enforced against those who were importing goods at the time it became effective as it would constitute an unconstitutional violation of their rights under both state and federal constitutions.