Kerr v. Clampitt was a United States Supreme Court case that addressed the issue of whether a contract between two parties was valid. The case involved a dispute between two parties, Kerr and Clampitt, over a contract for the sale of a tract of land. Kerr had agreed to purchase the land from Clampitt for a certain sum of money, but Clampitt refused to accept the payment and instead demanded a higher sum. Kerr then brought suit against Clampitt, claiming that the contract was valid and that Clampitt was obligated to accept the payment. The Supreme Court held that the contract was valid and that Clampitt was obligated to accept the payment. The Court reasoned that the contract was valid because it was supported by consideration, meaning that both parties had given something of value in exchange for the agreement. The Court also noted that the contract was not voidable due to any fraud or misrepresentation on the part of either party. As such, the Court held that Clampitt was obligated to accept the payment and that Kerr was entitled to the land.

Justice Field delivered the dissenting opinion in Kerr v. Clampitt, arguing that the majority's decision was contrary to established precedent and would lead to a dangerous expansion of judicial power. He argued that under prior decisions, courts had no authority to set aside an agreement between two parties on grounds other than fraud or mistake; here, however, the court had done exactly that by setting aside an agreement because it found it "unconscionable." This action constituted a usurpation of legislative power as only legislatures could make laws governing contracts between individuals. Justice Field also noted that while there were some cases where courts had refused to enforce agreements they deemed unconscionable due to public policy considerations, those cases involved situations where one party held all the bargaining power and thus did not represent true bargains at all - this case did not involve such circumstances. As such he concluded his dissent with a warning against allowing judges too much discretion in determining what is fair and just when enforcing contracts between private citizens.