Grier v. Wilt was a United States Supreme Court case that addressed the issue of whether a state court had the authority to issue a writ of habeas corpus to a prisoner held in a federal prison. The case involved a prisoner, John Grier, who was held in a federal prison in Pennsylvania. Grier had been convicted of a crime in the state of Maryland and was serving his sentence in the federal prison. Grier sought a writ of habeas corpus from the state court in Pennsylvania, arguing that he was being held in violation of his constitutional rights. 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 authority to interfere with the federal government's power 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 prisoner's detention, and not to challenge the merits of the underlying conviction. The Court's decision in Grier v. Wilt established that state courts do not have the authority to issue writs of habeas corpus to prisoners held in federal prisons. The decision also clarified the scope of the writ of habeas corpus, emphasizing that it is a remedy that can only be used to challenge the legality of a prisoner's detention, and not to challenge the merits of the underlying conviction.

Justice Grier delivered a dissenting opinion in the case of Grier v. Wilt, arguing that the majority's decision was not supported by precedent or sound legal reasoning. He argued that under Pennsylvania law, an executor had no authority to bring suit on behalf of a decedent's estate unless specifically authorized to do so by will or statute. In this case, there was neither authorization nor any other evidence indicating such authority existed; therefore, he concluded that the executor lacked standing and should have been dismissed from the action at its outset. Furthermore, Justice Grier noted that even if it were assumed for argument’s sake that an executor could sue without specific authorization from either will or statute—which he did not believe to be true—the court still erred in allowing recovery for damages sustained prior to his appointment as administrator since those claims belonged exclusively to heirs and distributees who had already obtained judgments against Wilt before his appointment as administrator. Thus, Justice Grier believed both grounds provided sufficient basis for reversing the judgment below and remanding with instructions dismissing plaintiff’s complaint due lack of standing and failure state claim upon which relief can be granted