Sims v. Everhardt 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 a prisoner, Sims, was held in a federal prison in Texas and sought a writ of habeas corpus from a state court. The state court granted the writ and ordered the prisoner to be released. The federal government then 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 fundamental right and that the state court should not interfere with the federal government's power to protect the rights of individuals. The Court's decision in Sims v. Everhardt 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 fundamental right that should not be interfered with by state courts.

In Sims v. Everhardt, the Supreme Court was tasked with determining whether a state court had jurisdiction to hear an appeal from a probate court in another state. The majority opinion held that the state court did not have jurisdiction and thus could not hear the case. Justice Field dissented, arguing that while it is true that states cannot interfere with each other's judicial proceedings, this does not mean they are unable to provide remedies for wrongs committed by citizens of one state against those of another. He argued further that if such remedies were unavailable then there would be no way for individuals who suffer injury due to actions taken in one state but reside in another to seek redress or justice through their own courts. Therefore he concluded that allowing appeals between different states should be allowed so long as it does not interfere with any existing laws or regulations governing interstate relations and commerce.