Farr v. Thomson et al. 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 held in a federal prison. The case arose when a prisoner, William Farr, was held in a federal prison in the District of Columbia. Farr sought a writ of habeas corpus from the Supreme Court of the District of Columbia, which was denied. Farr then appealed to the Supreme Court of the United States. 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 power to issue a 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 federal government had the power to protect that 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 a federal prison. The Court reasoned that the power to issue a 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 federal government had the power to protect that right.

In the case of Farr v. Thomson et al., the Supreme Court was tasked with deciding whether a state court had jurisdiction to hear an appeal from a federal district court in which it had already issued its final judgment. The majority opinion held that, under Article III of the Constitution, only Congress could grant such authority and thus ruled against allowing appeals from federal courts to state courts. Justice Field dissented on this point, arguing that while Congress may have been granted exclusive power over certain matters by Article III, there is nothing in the text or history of the document that would prevent states from exercising concurrent jurisdiction over cases arising out of their own laws and regulations. He further argued that if states were not allowed to exercise such powers then they would be rendered powerless when dealing with issues involving both state and federal law; as he put it: “The result must be either total paralysis or chaos”. Ultimately, his dissent was unsuccessful but serves as an important reminder about how closely intertwined our legal systems are at times and why we should strive for balance between them whenever possible