Deery v. Cray 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 held in a federal prison. The case arose when a prisoner, John Deery, was held in a federal prison in the District of Columbia. Deery sought a writ of habeas corpus from the Supreme Court of the District of Columbia, which was denied. Deery then appealed to the Supreme Court of the United States. 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 prerogative, 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 fundamental right, and that the state court should not be allowed to interfere with the federal government's power to imprison individuals. The Court's decision in Deery v. Cray 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 idea that the federal government has the power to imprison individuals without interference from the states.

In the case of Deery v. Cray, the Supreme Court was tasked with determining whether a contract between two parties could be enforced if it had been made in violation of an existing state law. The majority opinion held that such contracts were not enforceable and thus granted judgment for the defendant. However, Justice Field dissented from this decision on the grounds that he believed a court should not interfere with private agreements unless they are clearly contrary to public policy or morals. He argued that since there was no evidence presented at trial showing any harm caused by enforcing this particular agreement, it would be unjust to deny its enforcement simply because it violated an existing state law. Furthermore, Field reasoned that denying enforcement of such contracts would discourage people from entering into them altogether and thereby undermine their ability to make voluntary arrangements which benefit both parties involved without causing any detriment to society as a whole.