Baldwin v. Black is a United States Supreme Court case that was decided in 1886. The case involved a dispute between two parties over the ownership of a piece of land in the state of Illinois. The plaintiff, Baldwin, claimed that he had purchased the land from the defendant, Black, and that Black had failed to deliver the deed to the property. Black argued that he had never sold the land to Baldwin and that the deed was invalid. The Supreme Court ultimately sided with Baldwin, ruling that the deed was valid and that Baldwin was the rightful owner of the land. The Court held that the deed was valid because it had been signed by both parties and was witnessed by a third party. The Court also held that Black had no legal right to the land because he had failed to deliver the deed to Baldwin. This ruling established that a deed is valid if it is signed by both parties and witnessed by a third party, even if the deed is not delivered to the purchaser.

Justice Field delivered the dissenting opinion in Baldwin v. Black, 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 the Constitution to pass legislation regulating private contracts between individuals, as this was an issue reserved for state legislatures. Furthermore, he noted that even if such legislation were constitutional, it could not be applied retroactively as doing so would violate due process rights guaranteed by both state and federal constitutions. Justice Field concluded his dissent by noting that while Congress may have good intentions when passing laws like these, they are still unconstitutional because they exceed their limited powers granted by the Constitution.