In Parish v. United States, the Supreme Court of the United States was asked to decide whether a federal court had the power to issue a writ of habeas corpus to a prisoner held in a state prison. The petitioner, Parish, was a prisoner in a state prison in Louisiana. He had been convicted of a crime in a state court and was serving his sentence. He sought a writ of habeas corpus from a federal court, claiming that his conviction was unconstitutional. The Supreme Court held that the federal court did not have the power to issue a writ of habeas corpus to a prisoner held in a state prison. The Court reasoned that the writ of habeas corpus was a remedy for federal prisoners, and that the federal court did not have the power to interfere with the state court's judgment. The Court also noted that the writ of habeas corpus was not available to a prisoner held in a state prison, as the state court had already determined the legality of the conviction. The Court concluded that the federal court did not have the power to issue a writ of habeas corpus to a prisoner held in a state prison. The Court held that the writ of habeas corpus was a remedy for federal prisoners, and that the federal court did not have the power to interfere with the state court's judgment.

In the case of Parish v. United States, the Supreme Court was asked to decide whether a federal court had jurisdiction over an action brought by a citizen of one state against another state for damages caused by negligence in failing to keep its navigable waters free from obstructions. The majority opinion held that such actions could not be maintained in federal courts because they were barred under the Eleventh Amendment which prohibits suits against states without their consent. Justice Field dissented and argued that Congress has power to authorize citizens of one state to sue another state in federal court when it is necessary for protecting rights secured by treaty or act of Congress. He further argued that this power should extend even if it conflicts with the Eleventh Amendment since any amendment must yield before an express grant from Congress as provided for in Article VI, Clause 2 (the Supremacy Clause).