In Jones et al. v. Morehead, the Supreme Court ruled that a state legislature could not pass laws which would impair the obligation of contracts made by private citizens prior to such legislation being passed. The case involved two individuals who had contracted for an exchange of land in Kentucky before a law was passed prohibiting such exchanges without first obtaining permission from the county court. The plaintiffs argued that this new law violated their contract and thus should be declared unconstitutional as it impaired its obligations under Article I, Section 10 of the United States Constitution. The Supreme Court agreed with them and held that states cannot pass laws which interfere with existing contractual agreements between private parties unless there is some compelling public interest at stake or if Congress has specifically authorized such interference through federal legislation.

The dissenting opinion in the case of Jones et al. v. Morehead argued that the majority's decision to uphold a Kentucky state law allowing for imprisonment as punishment for debt was unconstitutional and violated Article I, Section 10 of the United States Constitution which states "No State shall pass any Bill of Attainder or ex post facto Law." The dissent argued that this law constituted an ex post facto law because it allowed creditors to imprison their debtors after they had already incurred their debts, thus punishing them retroactively and without due process. Furthermore, the dissent noted that such laws were not only unjust but also served no practical purpose since those who are imprisoned cannot pay off their debts while incarcerated. As such, they concluded that upholding this particular state statute would be contrary to both justice and common sense.