Trist v. Child is a United States Supreme Court case that was decided in 1874. The case involved a dispute between two parties over a contract for the sale of land. The plaintiff, Trist, had entered into a contract with the defendant, Child, to purchase a tract of land in Virginia. Trist had paid a portion of the purchase price and was in the process of making payments on the remainder when Child refused to complete the sale. Trist then brought suit against Child, claiming that Child had breached the contract and was liable for damages. The Supreme Court held that Trist was entitled to recover damages from Child for breach of contract. The Court reasoned that Trist had performed his part of the contract and had been ready and willing to complete the purchase. The Court also held that Child had not acted in good faith and had acted in a manner that was contrary to the terms of the contract. The Court's decision in Trist v. Child established the principle that a party who has performed his part of a contract is entitled to damages if the other party breaches the contract. This case is still cited today as an example of the importance of upholding contracts and the consequences of breaching them.

Justice Field delivered the dissenting opinion in Trist v. Child, arguing that Congress did not have the power to pass a law allowing citizens of one state to sue another state in federal court. He argued that this was an issue for individual states and their own courts, as it is contrary to the principles of sovereignty established by the Constitution. Furthermore, he argued that if Congress had such authority then they could also interfere with other matters traditionally left up to individual states' discretion such as taxation or police powers. Justice Field concluded his dissent by stating that while there may be cases where individuals are wronged by a state government but cannot find justice within its borders, those cases should instead be brought before Congress who can then decide whether or not legislation needs to be passed on behalf of those individuals.