RAND v. WALKER was a United States Supreme Court case that addressed the issue of whether a state court could enforce a contract that was made in violation of a state statute. The case involved a contract between two parties, Walker and Rand, in which Walker agreed to pay Rand a certain amount of money for the sale of a piece of property. The contract was made in violation of a state statute that prohibited the sale of property without a license. The Supreme Court held that the state court could not enforce the contract because it was made in violation of the state statute. The Court reasoned that the state statute was a valid exercise of the state's police power and that the state had the right to protect its citizens from fraud and other illegal activities. The Court also noted that the state had a legitimate interest in protecting its citizens from contracts that were made in violation of its laws. The Court's decision in RAND v. WALKER established that state courts could not enforce contracts that were made in violation of state statutes. This decision has been cited in numerous cases since then and has been used to support the idea that state courts should not enforce contracts that are made in violation of state laws.

Justice Field delivered the dissenting opinion in Rand v. Walker, arguing that the majority's decision was contrary to established precedent and would lead to a dangerous expansion of federal power. He argued that Congress had no authority under either the Thirteenth Amendment or any other constitutional provision to pass legislation prohibiting private individuals from entering into contracts with each other for labor services. Furthermore, he noted that if such an interpretation were allowed it would open up a wide range of activities which could be regulated by Congress without limit, thus creating an unconstitutional extension of federal power over matters traditionally left to state regulation. Justice Field concluded his dissent by noting that while he agreed with many aspects of the majority's opinion regarding slavery and its effects on African Americans, this case should not be used as justification for expanding congressional powers beyond what is explicitly stated in the Constitution.