Carson v. Hyatt & Another 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 mandamus to a federal court. The case involved a dispute between two parties, Carson and Hyatt, over a contract for the sale of a steamboat. Carson had filed a suit in a federal court in Louisiana to recover the purchase price of the steamboat, but the case was dismissed due to a lack of jurisdiction. Carson then filed a petition in the state court of Louisiana, asking for a writ of mandamus to be issued to the federal court, ordering it to hear the case. The Supreme Court held that the state court did not have the authority to issue a writ of mandamus to a federal court. The Court reasoned that the state court was not a superior court to the federal court, and thus did not have the power to issue such a writ. The Court also noted that the writ of mandamus was a remedy of last resort, and that the state court should have allowed the federal court to decide the case on its own merits. The Court concluded that the state court had no authority to issue the writ of mandamus, and thus the dismissal of the case in the federal court was proper.

In Carson v. Hyatt & Another, the Supreme Court was asked to decide whether a state court could enjoin a federal court from proceeding with an action that had been brought in it. The majority opinion held that such an injunction was not permissible because it would interfere with the exercise of jurisdiction by the federal courts and thus violate Article III of the Constitution. Justice Field dissented on this point, arguing that while he agreed with much of what was said in the majority opinion, he disagreed as to its conclusion regarding injunctions against proceedings before federal courts. He argued that there were certain cases where such injunctions might be appropriate if they did not interfere too greatly with judicial power or impede justice; for instance, when parties sought relief from multiple jurisdictions at once and needed protection from vexatious litigation or harassment by one party over another. Ultimately though, Justice Field concluded his dissent by noting his agreement with most aspects of the majority opinion but simply disagreeing on their ultimate conclusion about allowing state-court issued injunctions against proceedings before federal courts under some circumstances.