Dietzsch v. Huidekoper 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 Dietzsch and Huidekoper, in which Dietzsch agreed to sell Huidekoper a tract of land in exchange for a certain sum of money. Dietzsch had already received a portion of the money, but Huidekoper refused to pay the remainder. Dietzsch then sued Huidekoper for breach of contract. The Supreme Court held that the contract between Dietzsch and Huidekoper was valid and enforceable. The Court noted that the contract was clear and unambiguous, and that the parties had agreed to all of its terms. Furthermore, the Court held that Dietzsch had already performed his part of the contract by delivering the deed to the land, and that Huidekoper was therefore obligated to pay the remaining sum of money. The Court concluded that Dietzsch was entitled to recover the money from Huidekoper.

In Dietzsch v. Huidekoper, the United States Supreme Court was asked to decide whether a contract between two parties could be enforced when 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 thus was unenforceable under the law. However, Justice Field dissented from this decision on several grounds. He argued that there is no general rule of non-enforcement for contracts which violate state laws; rather, each case must be judged on its own merits and circumstances. Furthermore, he argued that even if such a rule did exist, enforcing this particular contract would not necessarily conflict with public policy as defined by Congress or any other body of government authority at the time of making the agreement. Finally, Justice Field noted that refusing to enforce contracts which are otherwise valid simply because they happen to violate some statute may have far-reaching implications for commerce and business transactions throughout America's legal system as a whole - something which should only occur after careful consideration has been given to all relevant facts and arguments in each individual case before reaching any conclusion about enforcement or non-enforcement thereof.