Ex parte Curtis is 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 federal custody. The case arose when a prisoner, Curtis, was held in federal custody in the state of Missouri. Curtis 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 federal custody. 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 detain a prisoner. The Court also noted that the writ of habeas corpus was a fundamental right, and that the state court should not interfere with the federal government's power to protect this right. 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 federal custody. 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 detain a prisoner.

In Ex Parte Curtis, the Supreme Court was asked to decide whether a writ of habeas corpus should be issued for an individual who had been convicted in a state court. The majority opinion held that the writ should not be issued because it would interfere with the power of the state courts and undermine their authority. However, Justice Field dissented from this decision. He argued that federal courts have jurisdiction over cases involving individuals who are unlawfully detained by state authorities and thus they can issue such writs when necessary to protect citizens' rights under federal law. Furthermore, he noted that if states were allowed to violate constitutional protections without consequence then those protections would become meaningless. Therefore, Justice Field concluded that issuing a writ of habeas corpus in this case was appropriate since it could help ensure justice for all parties involved regardless of which court system had jurisdiction over them