The Emily Souder case 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 Emily Souder, a prisoner in a federal prison, filed a petition for a writ of habeas corpus in a state court. The state court granted the writ and ordered the federal prison to release Souder. 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 imprison individuals. The Court also noted 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 imprison individuals. The Court's decision in the Emily Souder case established that state courts do not have the authority to issue writs of habeas corpus to prisoners held in federal prisons. The decision also established that the writ of habeas corpus is a federal power and that state courts do not have the authority to interfere with the federal government's power to imprison individuals.

In the case of The Emily Souder, Justice Field delivered a dissenting opinion. He argued that the majority's decision was based on an incorrect interpretation of the law and would lead to unjust results. According to Field, Congress had not intended for vessels such as The Emily Souder to be subject to seizure by foreign governments in cases where they were merely passing through their waters without any intention of trading or engaging in commerce with them. Furthermore, he noted that even if it could be assumed that Congress did intend for such seizures under certain circumstances, this particular vessel should have been exempt from seizure because its voyage was solely for humanitarian purposes and thus fell outside the scope of what Congress had originally intended when enacting laws regarding maritime trade. In conclusion, Justice Field believed that seizing The Emily Souder violated both international law and U.S policy towards foreign nations; therefore he dissented from the majority opinion which upheld her seizure by Mexico