Case v. Terrell was a United States Supreme Court case that was decided in 1870. The case involved a dispute between two parties over a contract for the sale of a slave. The plaintiff, Case, had entered into a contract with the defendant, Terrell, to purchase a slave for $1,000. Case paid the full amount, but Terrell refused to deliver the slave. Case then sued Terrell for breach of contract. The Supreme Court held that the contract was valid and enforceable. The Court noted that the contract was not illegal under the laws of the state in which it was made, and that the parties had the right to enter into such a contract. The Court also held that the contract was binding on both parties, and that Terrell was liable for breach of contract. The Court ordered Terrell to deliver the slave to Case and to pay damages for the breach. In its decision, the Supreme Court reaffirmed the principle that contracts for the sale of slaves were valid and enforceable. The Court also held that the parties to such contracts were bound by their terms and that the seller was liable for breach of contract if they failed to deliver the slave. This case established an important precedent for the enforcement of contracts involving the sale of slaves.

In the case of Case v. Terrell, the Supreme Court was asked to decide whether a contract between two parties could be enforced if it had been made in violation of an existing state law. The majority opinion held that such contracts were not enforceable and should be declared void by courts. However, Justice Field dissented from this decision on the grounds that enforcing these contracts would promote justice and fairness among individuals who have entered into valid agreements with each other despite any conflicting laws or regulations. He argued that allowing for enforcement of such contracts would encourage people to enter into legitimate business arrangements without fear of being punished for violating some obscure legal provision they may not even know exists. Furthermore, he reasoned that denying enforcement would lead to greater uncertainty in contractual relationships as well as create opportunities for fraudsters seeking to take advantage of unsuspecting victims through illegal means while still having their agreement upheld by a court due to its illegality under state law.