Duncan v. Jaudon 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 Duncan, was held in a federal prison in Florida. Duncan sought a writ of habeas corpus from the state court, claiming that he was being held in violation of his constitutional rights. 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 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 protect the rights of individuals. 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 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 protect the rights of individuals.

In the case of Duncan v. Jaudon, the Supreme Court was tasked with deciding whether a state court had jurisdiction to hear an appeal from a probate court in another state. The majority opinion held that it did not have such authority and dismissed the appeal. In his dissenting opinion, Justice Field argued that there was no clear legal precedent on this issue and thus it should be left up to each individual state to decide how they would handle appeals from other states' courts. He further noted that if Congress had intended for one state's laws to apply across all states, then they could have easily included language in their legislation making this explicit. Ultimately, he concluded that since Congress had not done so, it should be assumed that each individual state has full authority over its own judicial proceedings and can choose which cases are heard within its borders without interference from other states or federal law.