In Sawyer et al. v. Turpin et al., the Supreme Court of the United States was asked to decide whether a state court had the authority to issue a writ of habeas corpus to a prisoner who was being held in federal custody. The case arose when the petitioner, William Sawyer, was arrested and charged with a federal crime. He was then held in federal custody pending trial. Sawyer then filed a petition for a writ of habeas corpus in a state court, seeking to be released from federal custody. 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 federal custody. 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 a prisoner. The Court also noted that the writ of habeas corpus was a fundamental right, and that the federal government had the exclusive power to protect this right. The Court's decision in Sawyer et al. v. Turpin et al. established that the federal government has exclusive authority to issue writs of habeas corpus to prisoners held in federal custody. This decision has been cited in numerous subsequent cases, and it remains an important precedent in the area of federal habeas corpus law.

In Sawyer v. Turpin, the Supreme Court was asked to decide whether a state court had jurisdiction over an action brought by non-residents of that state against residents of the same state. The majority opinion held that such jurisdiction did exist and affirmed the decision of the lower court. However, Justice Field dissented from this ruling on two grounds: firstly, he argued that it violated due process for a non-resident to be sued in a forum with which they have no connection; secondly, he contended that allowing such suits would lead to "unjust discrimination" between citizens who are similarly situated but reside in different states. He concluded his dissent by noting that if Congress wished for such suits to be allowed then they should pass legislation explicitly granting authority for them rather than relying on judicial interpretation of existing laws.