Peninsular Iron Company v. Stone was a United States Supreme Court case that dealt with the issue of whether a contract between two parties was valid. The case involved a contract between the Peninsular Iron Company and Stone, a contractor. Stone had agreed to construct a bridge for the company, but the company refused to pay him for his work. Stone then sued the company for breach of contract. The Supreme Court held that the contract between the two parties was valid and enforceable. The Court found that the contract was supported by consideration, meaning that both parties had given something of value in exchange for the other's promise. The Court also found that the contract was not void for lack of mutuality, meaning that both parties had agreed to the same terms and conditions. The Court also held that the company was liable for breach of contract. The Court found that the company had failed to fulfill its obligations under the contract and had not paid Stone for his work. The Court ordered the company to pay Stone the amount due under the contract. In conclusion, the Supreme Court held that the contract between the Peninsular Iron Company and Stone was valid and enforceable. The Court also found that the company was liable for breach of contract and ordered it to pay Stone the amount due under the contract.

Justice Field delivered the dissenting opinion in Peninsular Iron Company v. Stone, arguing that the majority's decision was incorrect and should be reversed. He argued that a contract between two parties is binding on both of them, regardless of any subsequent changes to state law or regulations which may have been made after the contract had already been formed. In this case, he noted that there was an agreement between Peninsular Iron Company and Stone regarding payment for iron ore purchased by Stone from Peninsular Iron Company; however, due to a change in Michigan law after this agreement had already been established, it became impossible for either party to fulfill their obligations under the original terms of their contract. Justice Field believed that since neither party could be held responsible for failing to comply with these contractual obligations due to circumstances beyond their control (i.e., changes in state laws), they should not be liable for damages resulting from such non-compliance - rather than holding one party accountable while absolving another based solely on when certain legal statutes were enacted or amended.