Kehr v. Smith 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 Kehr, was held in a federal prison in Pennsylvania. Kehr sought a writ of habeas corpus from the state court, claiming that he was being held in violation of the Constitution. 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 Kehr v. Smith 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.

Justice Field delivered the dissenting opinion in Kehr v. Smith, arguing that the majority's interpretation of a contract between two parties was incorrect and should not be enforced. He argued that it would be unjust to allow one party to benefit from an agreement they had made with another when there were no clear terms or conditions specified by either side at the time of its formation. Furthermore, he asserted that if such agreements are allowed to stand without any specific language defining their scope and meaning, then it could lead to future disputes over what each party intended when entering into them. Finally, Justice Field concluded his dissent by noting that contracts should always have definite terms which clearly outline both parties' obligations so as to avoid confusion or misinterpretation down the line.