Blake v. McKim is a United States Supreme Court case that was decided in 1881. The case involved a dispute between two parties over a contract for the sale of a steamboat. The plaintiff, Blake, had contracted to purchase the steamboat from the defendant, McKim. However, McKim refused to deliver the boat, claiming that the contract was invalid because it had not been signed by both parties. The Supreme Court held that the contract was valid and enforceable. The Court reasoned that the contract was binding because it had been signed by one of the parties and the other party had accepted the terms of the contract. The Court also noted that the contract had been partially performed, as Blake had already paid a portion of the purchase price. The Court concluded that the contract was valid and enforceable, and that McKim was obligated to deliver the steamboat to Blake. The Court also held that McKim was liable for damages for breach of contract. This case established the principle that a contract is binding even if it is not signed by both parties, as long as one party has accepted the terms of the contract and the contract has been partially performed.

In Blake v. McKim, the United States Supreme Court was tasked with determining whether a contract between two parties could be enforced despite its illegality under state law. The majority opinion held that the contract was unenforceable due to its violation of public policy and thus not binding on either party. Justice Field dissented from this decision, arguing that contracts should only be invalidated if they are against federal or constitutional laws, as opposed to merely violating state statutes. He argued that it would be unfair for one party to benefit from their own illegal actions while punishing another who had no knowledge of such activities at the time of entering into an agreement with them. Furthermore, he noted that enforcing contracts is essential in maintaining trust and stability in business transactions; therefore any attempt by courts to undermine these agreements should only occur when absolutely necessary and never simply because a statute has been violated without more serious implications for society as a whole.