Robertson and Others v. Pickrell and Others 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 county court. The case was brought by the plaintiffs, Robertson and others, who sought to compel the county court to issue a writ of mandamus to the defendants, Pickrell and others, to compel them to pay a debt. The Supreme Court held that the state court did not have the authority to issue a writ of mandamus to the county court, as the county court was a separate and distinct court from the state court. The Court further held that the state court could not interfere with the county court's decision, as the county court was the proper court to decide the matter. The Court also held that the state court could not issue a writ of mandamus to the county court, as the county court was not subject to the jurisdiction of the state court. The Court concluded that the state court had no authority to issue a writ of mandamus to the county court, and the writ of mandamus was denied.

In Robertson and Others v. Pickrell and Others, the Supreme Court was asked to decide whether a certain deed of conveyance had been validly executed by an individual who was mentally incompetent at the time it was signed. The majority opinion held that the deed in question could not be enforced because it had been made without consideration or legal advice, and thus lacked any binding effect on either party. Justice Field dissented from this decision, arguing that while mental incompetence may have prevented the grantor from understanding what he was signing away, his signature still constituted a valid contract under state law since there were no other indications of fraud or duress present in its execution. Furthermore, Field argued that if such contracts are deemed invalid due to mental incapacity then all future transactions with those suffering from similar conditions would also be rendered void regardless of their circumstances; something which he felt should not be allowed as it would lead to unjust results for both parties involved.