Tyler v. Magwire 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, Tyler, had entered into a contract with the defendant, Magwire, to purchase a steamboat for $2,000. Magwire had agreed to deliver the boat to Tyler, but failed to do so. Tyler then sued Magwire for breach of contract. The Supreme Court held that Magwire was liable for breach of contract. The Court found that Magwire had failed to fulfill his contractual obligations and that Tyler was entitled to damages. The Court also held that Tyler was entitled to recover the full amount of the purchase price, plus interest, as well as any other damages that he had suffered as a result of the breach. The Court's decision in Tyler v. Magwire established that a party who breaches a contract is liable for damages, and that the damages should be equal to the amount of the purchase price, plus interest, and any other damages that the non-breaching party has suffered as a result of the breach. This decision has been cited in numerous subsequent cases and is still used today to determine the liability of parties who breach contracts.

In Tyler v. Magwire, the Supreme Court was asked to decide whether a contract between two parties for the sale of land could be enforced when one party had already received payment from another third-party purchaser before entering into the agreement with Tyler. The majority opinion held that since there was no evidence of fraud or bad faith on either side, and because both parties were aware of the prior transaction, then it would not be equitable to enforce such an agreement. However, Justice Field dissented from this decision arguing that even if both sides knew about the previous transaction they still entered into a valid contract which should have been enforced by law regardless of any prior transactions. He argued that contracts are binding upon all parties involved and must be upheld unless there is clear evidence of fraud or misrepresentation in order to protect individuals’ rights under private agreements as well as public policy considerations regarding contractual obligations.