In the case of Gray v. Darlington, the Supreme Court of the United States was asked to decide whether a contract between two parties was valid. The contract in question was between William Gray and William Darlington, and it involved the sale of a tract of land in Pennsylvania. Gray had agreed to sell the land to Darlington for a certain sum of money, but Darlington had failed to make the payment. Gray then sued Darlington for breach of contract. The Supreme Court held that the contract was valid and enforceable. The Court noted that the contract was in writing and that it had been signed by both parties. Furthermore, the Court found that the contract was supported by consideration, meaning that both parties had given something of value in exchange for the land. The Court also noted that the contract was not against public policy, and that it was not illegal or immoral. The Court ultimately held that the contract was valid and enforceable, and that Gray was entitled to recover the amount of money that Darlington had agreed to pay for the land. The Court also held that Darlington was liable for any damages that Gray had suffered as a result of the breach of contract.

Justice Field delivered the dissenting opinion in Gray v. Darlington, arguing that the majority's decision was incorrect and should be reversed. He argued that under Pennsylvania law, a contract of sale is not complete until delivery has been made to the buyer and accepted by them. In this case, there had been no such delivery or acceptance; instead, the seller had only agreed to deliver goods at some point in future when they were ready for shipment. Thus, Justice Field concluded that since there was no completed contract between Gray and Darlington prior to their dispute over payment terms - which resulted in Darlington refusing to ship any goods - then neither party could have breached it before its completion. Furthermore he noted that even if a breach did occur after completion of the contract due to non-payment on either side (which he believed unlikely), then both parties would still be liable for damages as per Pennsylvania law rather than just one being held responsible as decided by the majority ruling.