Ex parte Wall 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, Wall, was held in federal custody in the state of California. Wall sought a writ of habeas corpus from the state court, claiming that his imprisonment was illegal. 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 prerogative, 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 fundamental right, and that the federal government had the exclusive 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 prerogative, and that the state court did not have the authority to interfere with the federal government's power to imprison individuals.

In Ex Parte Wall, the Supreme Court was asked to decide whether a writ of habeas corpus should be issued in favor of William Wall. The majority opinion held that the writ should not be granted because it would interfere with Congress’s power to regulate Indian affairs and its exclusive authority over tribal matters. However, Justice Field dissented from this decision and argued that the Constitution does not grant Congress absolute control over Native American tribes; rather, it grants them only limited powers which must be exercised within certain constitutional limits. He further contended that if an individual is unlawfully detained by any agency or person acting under color of law then they are entitled to relief through a writ of habeas corpus regardless of their race or status as members of a tribe. As such, he believed that Mr. Wall had been wrongfully deprived his liberty without due process and deserved redress for his grievances through issuance of the requested writ