McClane v. Boon 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, William Boon, was held in a federal prison in the state of Maryland. Boon 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 power, 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 protect this right. The decision in McClane v. Boon established 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 decision also established that the writ of habeas corpus was a fundamental right that the federal government had the power to protect.

In McClane v. Boon, the Supreme Court was tasked with determining whether a contract between two parties could be enforced when it had been made without consideration. The majority opinion held that the contract was valid and enforceable because of its good faith nature and lack of fraud or deceit on either party's part. However, Justice Field dissented from this decision, arguing that contracts must have consideration in order to be legally binding and thus should not be enforced if they are lacking such an element. He argued further that allowing contracts to stand without any form of exchange would open up too many opportunities for abuse by one party over another due to their unequal bargaining power. As such, he concluded that while there may have been no ill intent in making the agreement at hand, it still did not meet all legal requirements necessary for enforcement under law.