Felix v. Scharnweber 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 who was being held in a federal prison. The case arose when a prisoner, Felix, was held in a federal prison in Wisconsin. Felix 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 remedy, and that the state court did not have the power to interfere with the federal government's authority to imprison individuals. The Court also noted that the writ of habeas corpus was a remedy that could only be used to challenge the legality of a person's detention, and not to challenge the conditions of the detention. 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 remedy, and that the state court did not have the power to interfere with the federal government's authority to imprison individuals.

In Felix v. Scharnweber, the United States Supreme Court was asked to decide whether a state court had jurisdiction over a case involving an alleged breach of contract between two parties from different states. The majority opinion held that the state court did not have jurisdiction because it lacked diversity of citizenship among the parties involved in the dispute. Justice Field dissented, arguing that under Article III of the Constitution and prior precedent established by this Court, Congress has authority to grant federal courts exclusive or concurrent jurisdiction over cases such as this one which involve citizens from different states. He argued further that since Congress had granted such power to federal courts through its passage of various statutes, then it should also be allowed for state courts as well when appropriate circumstances exist. In conclusion, he believed that if both sides agreed on having their dispute heard in a particular forum (in this case being a state court), then they should be allowed to do so without interference from either Congress or this Court's decision-making process.