Isaac Underhill v. Peggy F. Patton was a case heard by the United States Supreme Court in 1869. The case centered around a dispute between Underhill and Patton over a tract of land in the state of Virginia. Underhill had purchased the land from Patton in 1864, but Patton later attempted to reclaim the land, claiming that the sale was invalid due to a lack of consideration. The Supreme Court ultimately ruled in favor of Underhill, finding that the sale was valid and that Patton was not entitled to reclaim the land. The Court's decision was based on the fact that Underhill had paid a fair price for the land and that the sale was not fraudulent. Furthermore, the Court found that the consideration for the sale was sufficient, as Underhill had paid Patton the full amount of money that was agreed upon. The Court also noted that Patton had not provided any evidence to support her claim that the sale was invalid. As a result, the Court held that Underhill was the rightful owner of the land and that Patton was not entitled to reclaim it.

In the case of Issac Underhill v. Peggy F. Patton, the Supreme Court was asked to decide whether a deed executed by an emancipated slave in 1864 was valid and enforceable under Virginia law. The majority opinion held that it was not, as slaves were considered property rather than persons capable of entering into contracts at that time in Virginia. However, Justice Field dissented from this ruling on the grounds that slavery had been abolished by Congress prior to execution of the deed and thus any contract entered into after emancipation should be treated like any other contract between two parties regardless of race or former status as a slave. He argued further that denying validity to such contracts would amount to punishing freedmen for their previous enslavement and would be contrary both to public policy and natural justice.