In the case of Kingsbury v. Buckner, the Supreme Court of the United States ruled that a contract between two parties was valid and enforceable even though it was not in writing. The case involved a dispute between two parties, Kingsbury and Buckner, over a contract for the sale of a horse. Kingsbury had agreed to sell Buckner a horse for $100, but Buckner refused to pay the full amount. Kingsbury then sued Buckner for breach of contract. The Supreme Court held that the contract between Kingsbury and Buckner was valid and enforceable, even though it was not in writing. The Court reasoned that the parties had agreed to the terms of the contract, and that the agreement was supported by consideration. The Court also noted that the parties had acted in reliance on the agreement, and that the agreement was not against public policy. The Court's ruling in Kingsbury v. Buckner established the principle that oral contracts are valid and enforceable, even if they are not in writing. This ruling has been cited in numerous cases since then, and it has been used to support the validity of oral contracts in a variety of contexts.

In the Supreme Court case of Kingsbury v. Buckner, Justice Field delivered a dissenting opinion in which he argued that the majority’s decision was wrongfully based on an erroneous interpretation of the law. He believed that under Missouri state law, Buckner had a valid claim to ownership over certain property and should have been allowed to keep it despite Kingsbury's attempt to take possession through adverse possession. In his dissent, Justice Field noted that while there were some discrepancies between what each party claimed about their respective rights regarding the land in question, these inconsistencies did not necessarily mean that one side or another was lying; rather they could be attributed simply to different interpretations of how Missouri laws applied in this particular situation. Furthermore, he argued that even if both parties had made mistakes with regard to their understanding of applicable legal principles and statutes related to adverse possession claims, this should not result in either party being deprived from asserting their rightful title over said property as provided by state law.