Ex parte Bigelow was a United States Supreme Court case that dealt with the issue of whether a state court could issue a writ of habeas corpus to a prisoner who was being held in a federal prison. The petitioner, Bigelow, was a prisoner in a federal prison in Massachusetts. He had been convicted of a federal crime and was serving his sentence in the federal prison. Bigelow filed a petition for a writ of habeas corpus in the state court, arguing that he was being held in violation of his constitutional rights. The Supreme Court held that the state court did not have the authority to issue a writ of habeas corpus to a prisoner 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 its citizens. The Court also noted that the writ of habeas corpus was a remedy for violations of federal law, and that the state court did not have the power to enforce federal law. The Court's decision in Ex parte Bigelow established that state courts do not have the authority to issue writs of habeas corpus to prisoners in federal prisons. This decision has been cited in numerous subsequent cases involving the issue of state court jurisdiction over federal prisoners.

In Ex Parte Bigelow, 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 citizens of 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. However, Justice Field dissented from this decision and argued that under Article III Section 2 Clause 1 of the U.S Constitution, which grants federal courts original jurisdiction over cases involving citizens from different states, Congress could grant concurrent or exclusive jurisdiction to state courts for such cases as well. He further argued that since Congress has not acted on this matter yet, it is up to each individual State's legislature to determine if they wish their own courts to exercise such power or not. In conclusion he stated that since Massachusetts had granted its own Courts with concurrent jurisdictional authority in similar matters then there should be no reason why they cannot do so here as well and thus allow them to hear this particular case at hand.