Fowler v. Rathbones 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 steamboat. The plaintiff, Fowler, had entered into a contract with the defendant, Rathbones, to purchase a steamboat for $2,000. Fowler paid the full amount of the purchase price, but Rathbones refused to deliver the steamboat. The Supreme Court held that the contract was valid and enforceable. The Court found that the contract was supported by consideration, as Fowler had paid the full purchase price. The Court also found that the contract was not voidable due to any lack of capacity on the part of Fowler, as he was a competent adult. The Court further held that Rathbones had breached the contract by refusing to deliver the steamboat, and that Fowler was entitled to damages for the breach. The Court ordered Rathbones to pay Fowler the full purchase price of the steamboat, plus interest.

In Fowler v. Rathbones, 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 the contract should not be enforced because it violated public policy and would undermine the authority of state legislatures to regulate commerce within their borders. However, Justice Field dissented from this decision and argued that contracts are binding regardless of any violations they may have committed against local laws or regulations. He reasoned that enforcing such contracts is necessary for upholding private property rights and protecting individuals from arbitrary interference by government officials who might otherwise choose which contracts they wish to enforce based on personal preference rather than legal principles. Furthermore, he argued that allowing states to invalidate contractual agreements at will would lead to chaos as businesses attempt to navigate conflicting laws across different jurisdictions while trying conduct business transactions with each other.