Porter v. Graves 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 federal custody. The case arose when the petitioner, Porter, was arrested by federal officers and held in federal custody. The state court issued a writ of habeas corpus to the federal officers, ordering them to produce Porter before the court. The federal officers refused to comply with the writ, arguing that the state court did not have the authority to issue the writ. The Supreme Court held that the state court did not have the authority to issue the writ of habeas corpus. 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 individuals. The Court further held 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 enforce its laws. The Court's decision in Porter v. Graves established that state courts do not have the authority to issue writs of habeas corpus to individuals held in federal custody. The decision also established that the writ of habeas corpus is a federal remedy, and that state courts do not have the authority to interfere with the federal government's power to enforce its laws.

Justice Field delivered the dissenting opinion in Porter v. Graves, arguing that the majority's decision was contrary to both law and equity. He argued that under Missouri state law, a contract for services rendered could not be enforced against an executor of an estate unless it had been approved by the probate court prior to payment being made. The plaintiff in this case had provided services to a decedent before his death but did not receive approval from the probate court until after he received payment from the executor of the estate; thus, Justice Field argued that there was no legal basis for enforcing such a contract against him as executor. Furthermore, he noted that even if there were some equitable grounds on which to enforce such contracts without prior approval from a probate court (which he believed there were none), those grounds would still have failed here because they require proof of "good faith" on behalf of all parties involved - something which could not be established in this case due to lack of evidence regarding either party's intentions or actions at any point during their dealings with each other.