In the case of Marks v. United States in 1895, the Supreme Court ruled on a dispute over land ownership. The plaintiff, Marks, claimed that he had purchased certain lands from Native American tribes under an act of Congress passed in 1834 which allowed such transactions with presidential approval. However, President Andrew Johnson had issued a proclamation declaring these sales void unless they were ratified by Congress - something that did not occur for this particular sale until after Marks' death. The defendant was the U.S government who argued that because ratification occurred posthumously and without any specific provision for retroactivity, it could not be applied to validate Mark's purchase retrospectively. The court sided with the government stating that while acts of congress are generally presumed to operate prospectively unless expressly declared otherwise or clear intent can be inferred from their language/context/history; none of those conditions were met here so there was no basis to apply ratification retroactively. This decision affirmed federal supremacy over tribal lands and underscored how congressional actions (or lack thereof) can significantly impact property rights even when private parties have seemingly followed all existing laws/regulations at time of transaction.

In the dissenting opinion for Marks v. United States, Justice Harlan argued that the majority's interpretation of the Ex Post Facto Clause was too narrow and failed to protect citizens from retroactive punishment. He contended that any law which makes an action punishable in a manner it was not when committed is ex post facto, regardless of whether or not it technically increases punishment severity. In this case, he believed that applying revised criminal statutes to actions committed before their enactment constituted such a violation. Furthermore, he disagreed with the majority's view on "cruel and unusual" punishments; while they held only punishments considered cruel/unusual at time of Constitution adoption were prohibited, Harlan asserted evolving societal standards should be taken into account as well - thus potentially deeming certain previously acceptable penalties unconstitutional today.