Thorwegan v. King 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, Thorwegan, was held in a federal prison in the state of Wisconsin. Thorwegan sought a writ of habeas corpus from the state court, claiming that he was being held in violation of his constitutional rights. 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 conditions of the detention. 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 Thorwegan v. King, arguing that the majority had misapplied the law and failed to consider all relevant facts of the case. He argued that under California's Civil Code, a married woman was entitled to her separate property and could not be deprived of it by her husband without due process of law. The court should have considered this code when making its decision as well as other evidence presented at trial which showed that Mrs. King had acquired certain properties before marriage with money she earned from teaching school or inherited from family members who died prior to her marriage; these properties were clearly hers alone and thus exempt from any claims made by Mr. King upon their divorce proceedings. Justice Field concluded his dissent by noting that if Mrs Kings' rights were violated then so too would those of every married woman in California whose separate property is put at risk whenever they are divorced or separated from their husbands without proper legal protection for such assets being provided beforehand.