Gill v. Wells was a United States Supreme Court case that addressed 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, John Gill, was held in a federal prison in the state of Maryland. Gill sought a writ of habeas corpus from the state court, claiming that he was being held in violation of the Constitution. 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 a federal prison. The Court reasoned that the writ of habeas corpus was a federal remedy, and that the state court did not have the power to interfere with the federal government's authority to imprison individuals. The Court also noted that the writ of habeas corpus was a remedy that could only be used to challenge the legality of a person's detention, and not to challenge the merits of the underlying conviction. 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 a federal prison. The Court reasoned that the writ of habeas corpus was a federal remedy, and that the state court did not have the power to interfere with the federal government's authority to imprison individuals.

Justice Field delivered the dissenting opinion in this case. He argued that the majority's decision was contrary to both law and equity, as it allowed a party to take advantage of their own wrongs. The defendant had originally purchased land from one person, but then sold it to another without disclosing that they did not have clear title or any legal right to sell it. Justice Field believed that since the defendant had acted in bad faith by selling something they knew was not rightfully theirs, they should be held liable for damages caused by their actions rather than being able to keep all of the money received from sale of the property. Furthermore, he argued that allowing them do so would set a dangerous precedent where people could commit fraud with impunity and still benefit financially from such acts.