Mephams v. Biesser 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 Mephams and Biesser, in which Mephams agreed to pay Biesser a certain amount of money for the use of a certain piece of land. Biesser had previously agreed to sell the land to Mephams, but the contract was never finalized. The Supreme Court held that the contract between Mephams and Biesser was valid and enforceable. The Court reasoned that the contract was binding because it was made in good faith and with the intention of being legally binding. The Court also noted that the contract was supported by consideration, meaning that both parties had given something of value in exchange for the contract. The Court also held that the contract was not voidable due to any lack of capacity on the part of either party. The Court noted that both parties were of sound mind and had the capacity to enter into a contract. Ultimately, the Supreme Court held that the contract between Mephams and Biesser was valid and enforceable. The Court's decision established that contracts between two parties can be legally binding even if they are not finalized.

In Mephams v. Biessle, the Supreme Court was tasked with determining whether a contract between two parties could be enforced when it had been made without consideration and in violation of a state statute. The majority opinion held that the contract was unenforceable because it lacked consideration and violated public policy as expressed by the state law. However, Justice Field dissented from this decision on both grounds. He argued that while contracts lacking consideration are generally unenforceable, there is an exception for those which have been partially performed or relied upon to some degree; he believed that such an exception should apply here since one party had already begun performing their obligations under the agreement before its illegality became known to them. Additionally, he argued that even if no performance has occurred yet, courts can still enforce contracts which violate statutes if they do not conflict with any fundamental principles of justice or morality - something he did not believe applied in this case given how minor the offense was compared to other violations of similar laws elsewhere in society at large.