Matthews v. McStea 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 who was being held in a federal prison. The case arose when a prisoner, John McStea, was held in a federal prison in the state of New York. McStea sought a writ of habeas corpus from the state court, claiming that he was being held in violation of his constitutional rights. The state court granted the writ, and the federal government appealed the decision to the Supreme Court. The Supreme Court held that the state court did not have the authority to issue a writ of habeas corpus to a prisoner held in a federal prison. The Court reasoned that the writ of habeas corpus was a federal remedy, and that the state court did not have the power to interfere with the federal government's authority to imprison individuals. The Court also noted that the writ of habeas corpus was a remedy that could only be used to challenge the legality of a person's detention, and not to challenge the conditions of the detention. The Court's decision in Matthews v. McStea established that state courts do not have the authority to issue writs of habeas corpus to prisoners held in federal prisons. This decision has been cited in numerous subsequent cases, and has been used to support the principle that state courts cannot interfere with the federal government's authority to imprison individuals.

In Matthews v. McStea, the Supreme Court was tasked with determining whether a contract between two parties could be enforced even though it had not been signed by both parties. The majority opinion held that the contract was valid and enforceable because there was sufficient evidence of an agreement between the two parties, including their course of conduct in relation to each other. However, Justice Field dissented from this opinion on the basis that contracts must be written and signed by both parties in order for them to be legally binding. He argued that without such a requirement, any verbal agreement or promise would become enforceable as long as one party claimed they had made it; thus creating uncertainty and confusion about what is actually required for a contract to exist under law. Furthermore, he noted that allowing oral agreements would open up potential avenues for fraud since people could make false claims about having entered into certain contracts without being able to provide proof of those agreements through signatures or writing documents down