Drury v. Hayden was a United States Supreme Court case that addressed the issue of whether a state court could issue a writ of habeas corpus to a prisoner who was being held in federal custody. The case arose when a prisoner, Drury, was arrested in the state of Missouri and charged with a federal crime. He was then transferred to a federal prison in Kansas. Drury then filed a petition for a writ of habeas corpus in the state court of Missouri, arguing that he was being unlawfully detained. The state court granted the writ and ordered the federal prison to release Drury. The federal government then appealed the decision to the Supreme Court, arguing that the state court did not have the authority to issue a writ of habeas corpus to a prisoner in federal custody. The Supreme Court agreed with the federal government, ruling that the state court did not have the authority to issue a writ of habeas corpus to a prisoner in federal custody. The Court reasoned that the writ of habeas corpus was a federal power, 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 right to protect its own power to detain prisoners.

In Drury v. Hayden, the Supreme Court was asked to decide whether a deed of trust executed by a husband and wife constituted an equitable mortgage or an absolute conveyance. The majority opinion held that it was an absolute conveyance, but Justice Field dissented from this decision. He argued that the language used in the deed indicated that it should be considered as creating only a security interest for repayment of debt rather than transferring title outright to the grantee. Furthermore, he noted that there were other facts which suggested strongly that this transaction was intended as a loan secured by real property rather than simply conveying ownership away from its original owners. In conclusion, Justice Field believed these factors combined showed clearly enough to make out an equitable mortgage under applicable law and thus overturning the lower court's ruling on appeal would have been appropriate in his view.