United States v. MacDonald was a United States Supreme Court case that dealt with the issue of whether a state court had the authority to issue a writ of habeas corpus to a prisoner held in federal custody. The case arose when a prisoner, John MacDonald, was arrested by federal authorities in California and held in federal custody. MacDonald sought a writ of habeas corpus from the California Supreme Court, which the court granted. The United States government then appealed the decision to the United States Supreme Court. The Supreme Court held that the California Supreme Court did not have the authority to issue a writ of habeas corpus to a prisoner held in federal custody. The Court reasoned that the writ of habeas corpus was a federal prerogative, and that the state court did not have the authority to interfere with the federal government's power to detain a prisoner. The Court also noted that the writ of habeas corpus was a fundamental right, and that the federal government had the right to protect its own interests in the matter. In conclusion, the Supreme Court held that the California Supreme Court did not have the authority to issue a writ of habeas corpus to a prisoner held in federal custody. The Court reasoned that the writ of habeas corpus was a federal prerogative, and that the state court did not have the authority to interfere with the federal government's power to detain a prisoner. The Court also noted that the writ of habeas corpus was a fundamental right, and that the federal government had the right to protect its own interests in the matter.

In United States v. MacDonald, the Supreme Court was asked to decide whether a defendant who had been convicted of manslaughter in a state court could be tried again for the same crime by federal authorities. The majority opinion held that double jeopardy did not apply and thus allowed for retrial in this case. However, Justice Field dissented from this decision on the grounds that it violated both common law principles and constitutional protections against double jeopardy. He argued that allowing multiple trials would lead to oppressive prosecutions as well as an increased risk of conviction based on unreliable evidence or false testimony due to witnesses being called upon multiple times during different proceedings. Furthermore, he noted that such practices were contrary to established legal precedent which prohibited successive prosecutions for the same offense under any circumstances unless expressly authorized by Congress or provided for in some other form of legislation.