Thornton v. Carson was a United States Supreme Court case that addressed the issue of whether or not an individual could be held liable for damages caused by his slave. The plaintiff, Thornton, had loaned his slave to the defendant, Carson. While in Carson's possession and care, the slave damaged some property belonging to Thornton which resulted in him filing suit against Carson for compensation. The court ruled that since slavery is illegal under common law and therefore cannot be enforced as a contract between two individuals; thus it found no liability on behalf of the defendant due to lack of contractual agreement between them regarding ownership of said slave at time damage occurred. This decision established precedent that an owner may not hold another person responsible for any damages caused by their slaves while they are out of their control or custody unless there is evidence proving otherwise such as proof of prior contractual agreement between parties involved with regard to ownership rights over said slaves at time damage occurred

In Thornton v. Carson, the Supreme Court held that a state court had no authority to issue an injunction against a federal officer who was carrying out his official duties. The dissenting opinion argued that the Constitution did not grant exclusive jurisdiction over such matters to either the federal or state courts and thus both should have concurrent jurisdiction in this case. Furthermore, it was argued that since Congress had not provided any specific remedy for cases like this one, then it would be up to each individual state court to decide how best to handle them. Finally, it was contended that if states were denied their right of self-government by being unable to protect its citizens from unconstitutional acts committed by federal officers within their borders then they could become subject "to all sorts of oppression."