Miller v. McKenzie was a United States Supreme Court case decided in 1870. The case involved a dispute between two parties over a contract for the sale of a steamboat. The plaintiff, Miller, had contracted with the defendant, McKenzie, to purchase a steamboat for $2,000. Miller paid the full amount, but McKenzie refused to deliver the boat. Miller then sued McKenzie for breach of contract. The Supreme Court held that Miller was entitled to recover the full amount of the purchase price, plus interest, from McKenzie. The Court reasoned that the contract was valid and enforceable, and that McKenzie had breached it by failing to deliver the boat. The Court also held that Miller was entitled to recover interest on the purchase price, as the contract had specified that interest would be paid if the purchase price was not paid in full. In conclusion, the Supreme Court held that Miller was entitled to recover the full purchase price of the steamboat, plus interest, from McKenzie for breach of contract.

In Miller v. McKenzie, the Supreme Court was tasked with determining whether a contract between two parties that had been made in one state and then partially performed in another could be enforced by the courts of the latter state. The majority opinion held that such contracts were not enforceable under the Full Faith and Credit Clause of Article IV of the U.S Constitution because they did not meet all requirements for enforcement as set forth by Congress. Justice Field dissented from this decision, arguing that it would lead to an absurd result wherein citizens who move to different states are unable to enforce their contractual obligations due solely to where they reside at any given time. He further argued that if Congress intended for these types of contracts to be unenforceable, it should have explicitly stated so rather than leaving it up to interpretation by individual states or judges within those states.