Brown v. Kennedy was a United States Supreme Court case that was decided in 1872. The case involved a dispute between two parties over a contract for the sale of a steamboat. The plaintiff, Brown, had contracted with the defendant, Kennedy, to purchase a steamboat for $2,000. Brown paid the full amount, but Kennedy refused to deliver the boat. Brown then sued Kennedy for breach of contract. The Supreme Court held that Kennedy was liable for breach of contract. The Court found that Kennedy had failed to fulfill his contractual obligations and that Brown was entitled to damages. The Court also held that Brown was entitled to recover the full amount of the purchase price, plus interest. The Court's decision in Brown v. Kennedy established the principle that a party who breaches a contract is liable for damages. This decision has been cited in numerous subsequent cases involving breach of contract. The Court's decision in this case has been cited as an example of the importance of upholding the sanctity of contracts.

In the case of Brown v. Kennedy, the Supreme Court was asked to decide whether a contract between two parties could be enforced if it had been made in violation of state law. The majority opinion held that such contracts were not enforceable and should be void. Justice Field dissented from this decision, arguing that while states have the power to regulate certain types of contracts, they do not have authority over all contractual agreements. He argued that when both parties are willing participants in an agreement and there is no fraud or misrepresentation involved, then courts should uphold those agreements regardless of any state laws which may conflict with them. Furthermore, he noted that allowing states to invalidate private contracts would lead to uncertainty for businesses as well as individuals who rely on these arrangements for their livelihoods and economic security.