Ex parte Schwab was a United States Supreme Court case that dealt with the issue of habeas corpus. The case involved a man named Charles Schwab, who was convicted of murder in the state of Pennsylvania. Schwab had been sentenced to death, but he filed a petition for a writ of habeas corpus, arguing that his conviction was unconstitutional. The Supreme Court ultimately ruled in Schwab's favor, holding that the writ of habeas corpus was available to him and that his conviction was unconstitutional. The Court's decision in Ex parte Schwab was based on the fact that Schwab had been denied the right to a jury trial. The Court held that the Sixth Amendment to the United States Constitution guarantees the right to a jury trial in all criminal cases, and that this right could not be denied to Schwab. The Court also held that the writ of habeas corpus was available to Schwab, and that he was entitled to a new trial. In its decision, the Court also noted that the writ of habeas corpus is an important safeguard of individual liberty, and that it should not be denied to individuals who have been wrongfully convicted. The Court's decision in Ex parte Schwab was an important victory for the protection of individual rights, and it established the principle that the writ of habeas corpus is available to individuals who have been wrongfully convicted.

In Ex Parte Schwab, the Supreme Court was tasked with determining whether a writ of habeas corpus should be granted to Charles Schwab. The majority opinion held that it should not be granted because the petitioner had been convicted by a court-martial and therefore did not have any legal authority to challenge his conviction in civil courts. Justice Field dissented from this decision, arguing that while military tribunals may have jurisdiction over certain matters related to military personnel, they do not possess absolute power over all aspects of their lives. He argued that due process must still apply when an individual is accused of a crime and thus habeas corpus should still be available as a means for challenging convictions obtained through such proceedings. Furthermore, he noted that Congress has specifically authorized federal courts to issue writs of habeas corpus in cases involving individuals who are being unlawfully detained or imprisoned by state authorities; thus there is no reason why similar protection could not also extend to those subject to court-martials conducted under federal law.