Robert Ruffin Barrow brought a case against Josiah Reab to the Supreme Court. Barrow had been convicted of murder in Louisiana and was sentenced to death, but he argued that his conviction should be overturned because it violated the Constitution's prohibition on ex post facto laws. The court ruled that although Louisiana did not have an explicit law prohibiting such convictions, its constitution prohibited them implicitly. Therefore, they found for Barrow and reversed his conviction. This decision established precedent for future cases involving similar constitutional issues by affirming that states must abide by their own constitutions even if those constitutions do not explicitly prohibit certain actions or behaviors.

In the case of Robert Ruffin Barrow v. Josiah Reab, Justice McLean delivered a dissenting opinion in which he argued that the plaintiff had failed to prove his right to recover damages from the defendant. He believed that there was no evidence presented at trial showing any actual damage suffered by the plaintiff as a result of an alleged breach of contract between them. Furthermore, Justice McLean noted that even if such evidence were present, it would be insufficient for recovery since it did not appear that any consideration had been given by either party in exchange for their agreement and thus could not form a valid contract under Georgia law. In conclusion, Justice McLean concluded that while he sympathized with the plight of Mr. Barrow, he felt compelled to dissent due to lack of proof on behalf of him or his counsel regarding this matter before court and therefore found against him in this instance.