In United States v. Workman et al., the Supreme Court held that a soldier in the Confederate Army could not be tried for treason against the United States, as he was never legally subject to its laws or allegiance. The case arose when three men were indicted by a grand jury in Virginia for treason against the Union during their service with Confederate forces. The defendants argued that they had never been citizens of any state and thus could not owe allegiance to any government other than their own, which did not recognize U.S. authority over them at the time of their alleged offense. In an opinion written by Chief Justice Salmon P Chase, the court agreed with this argument and found that since there was no legal obligation on behalf of these individuals to obey U.S law, they could not be convicted of treason under it either; accordingly, all charges were dismissed without prejudice

In United States v. Workman et al., the Supreme Court was asked to decide whether a soldier could be tried by a military court for an offense committed while in service, even if he had already been acquitted of that same crime by a civil court. The majority opinion held that such double jeopardy did not exist and the accused could be retried in military court. However, Justice Grier dissented from this decision on two grounds: firstly, because it violated the Fifth Amendment's prohibition against double jeopardy; and secondly, because it allowed Congress to pass laws which would supersede state laws without violating Article VI of the Constitution. He argued that allowing soldiers to be tried twice for one offense undermined public confidence in both civilian and military justice systems as well as undermining constitutional protections afforded all citizens under federal law.