Osborn v. United States was a United States Supreme Court case that dealt with the issue of whether a federal court had the authority to issue a writ of error to a state court. The case was brought by William Osborn, who had been convicted of a crime in a state court. Osborn argued that the state court had erred in its decision and that the federal court should have the power to review the state court's decision. The Supreme Court held that the federal court did not have the authority to issue a writ of error to a state court. The Court reasoned that the Constitution did not grant the federal court the power to review state court decisions, and that the power to review state court decisions was reserved to the state courts. The Court also noted that the writ of error was a common law remedy, and that the federal court did not have the power to issue such a writ. The Court's decision in Osborn v. United States established that the federal court did not have the power to review state court decisions. This decision has been cited in numerous cases since then, and it has been used to support the idea that the federal court should not interfere with state court decisions.

In Osborn v. United States, the Supreme Court was asked to decide whether a state court could issue an injunction against a federal officer in order to prevent him from performing his official duties. The majority of the Court held that such an action was unconstitutional and would be considered as interference with the performance of federal functions. Justice Field dissented, arguing that states have inherent authority over their own citizens and can take steps necessary for their protection when it comes into conflict with federal law or policy. He argued that this case should not be decided on constitutional grounds but rather on practical considerations; if states are unable to protect its citizens from harm caused by improper actions taken by federal officers then they will become powerless before them, thus undermining public confidence in government institutions. Furthermore, he argued that allowing state courts to issue injunctions against federal officers is consistent with other cases where similar remedies were allowed without any constitutional challenge being raised at all.