Fowler v. Rapley 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 a prisoner, John Fowler, was held in federal custody in the state of New York. Fowler sought a writ of habeas corpus from the state court, which the court granted. The federal government then 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 state court should not be allowed to interfere with the federal government's power to protect this right. In conclusion, 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 state court should not be allowed to interfere with the federal government's power to protect this right.

In Fowler v. Rapley, the Supreme Court was tasked with determining whether a contract between two parties could be enforced when one of the parties had died before it was fully executed. The majority opinion held that since only part of the agreement had been completed at the time of death, and no consideration had passed from either party to complete their respective obligations under the contract, it could not be enforced against either party's estate. Justice Field dissented from this decision on several grounds. He argued that if both parties intended for an agreement to exist and were in good faith attempting to execute its terms prior to one of them dying, then there should have been some form of equitable relief available so as not to leave any injustice unaddressed by denying enforcement altogether. Furthermore, he noted that even though consideration may not have passed between both sides yet due to death intervening before completion occurred; nevertheless there still existed sufficient evidence in support of enforcing such contracts through equity principles which would allow courts greater flexibility in deciding cases like these where justice demands a remedy beyond what is provided by traditional common law rules alone.