Ex parte Carll 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 federal custody. The case arose when a prisoner, Carll, was held in federal custody in New York and sought a writ of habeas corpus from the state court. 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 the writ of habeas corpus. 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. The Court's decision in Ex parte Carll established that the state court did not have the authority to issue a writ of habeas corpus to a prisoner held in federal custody. The decision also established that the writ of habeas corpus was a fundamental right that should be protected by the federal government.

In Ex Parte Carll, the United States Supreme Court was asked to decide whether a state court had jurisdiction over certain property located in another state. The majority opinion held that the state court did not have jurisdiction because it lacked personal service of process on the defendant and therefore could not exercise its power beyond its own borders. Justice Field dissented from this decision, arguing that due process does not require personal service of process when there is an adequate substitute for such service available. He argued that since notice by publication was given in this case, it should be considered sufficient to satisfy due process requirements and thus allow the state court to exercise jurisdiction over out-of-state property.