Tucker v. Spalding 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, Tucker, was held in a federal prison in the state of Illinois. Tucker sought a writ of habeas corpus from the state court, which was denied by the federal 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 power to issue a 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 held that the state court could not interfere with the federal government's power to enforce its laws. The decision in this case established the principle that state courts do not have the authority to issue writs of habeas corpus to prisoners held in federal prisons.

In Tucker v. Spalding, the Supreme Court was asked to decide whether a contract between two parties could be enforced if it had been made in violation of state law. The majority opinion held that the contract should not be enforced because it violated state law and public policy. However, Justice Field dissented from this decision on the grounds that enforcing contracts is an important part of upholding private property rights and protecting individuals’ freedom to enter into agreements with one another without interference from government or other third parties. He argued that since there was no evidence of fraud or bad faith by either party involved in making the agreement, they should both have their expectations fulfilled according to its terms regardless of any legal violations which may have occurred during its formation. In his view, allowing such contracts would provide greater stability for business transactions and encourage people to engage in commerce more freely knowing their agreements will be respected even when mistakes are made along the way.