Merriam v. United States was a United States Supreme Court case that addressed the issue of whether a federal court had the authority to issue a writ of habeas corpus to a prisoner who was being held in a state prison. The case arose when the petitioner, Merriam, was convicted of a crime in a state court and sentenced to a term of imprisonment. Merriam then filed a petition for a writ of habeas corpus in a federal court, arguing that his conviction was unconstitutional. The federal court granted the writ and ordered Merriam's release from prison. The United States government appealed the decision to the Supreme Court, arguing that the federal court did not have the authority to issue the writ of habeas corpus. The Supreme Court agreed with the government, holding that the federal court did not have the authority to issue the writ of habeas corpus in this case. The Court reasoned that the writ of habeas corpus was a remedy that was available only to prisoners held in federal custody, and not to those held in state custody. As such, the Court held that the federal court did not have the authority to issue the writ of habeas corpus in this case.

Justice Field delivered the dissenting opinion in Merriam v. United States, arguing that Congress had exceeded its constitutional authority by enacting a law to punish individuals for contempt of court without providing them with an opportunity to be heard. He argued that this violated the Fifth Amendment's due process clause, which guarantees citizens certain rights when they are accused of a crime or subjected to government action. Furthermore, he noted that such laws should not be passed unless there is some clear and immediate danger posed by those who refuse to obey orders from courts or other public authorities. In his view, no such danger existed in this case as Mr Merriam was simply refusing to answer questions about matters unrelated to any criminal proceedings against him; thus it would have been more appropriate for the Court itself rather than Congress to address his refusal through sanctions imposed directly on him rather than passing a general law applicable across all cases involving contemptuous behavior towards federal courts.