The Mechanics' Bank of Alexandria v. Withers was a case heard by the United States Supreme Court in 1821. The dispute centered around whether or not the bank had to pay interest on notes that were issued prior to the adoption of an act which allowed for such payments. The court ultimately ruled in favor of Withers, finding that he was entitled to receive interest from the date when his note became due and payable, regardless of when it was issued. This decision established precedent regarding contracts made before laws are passed and set forth guidelines for how those contracts should be interpreted going forward. It also reinforced existing common law principles related to contract formation and enforcement, as well as clarified what rights parties have under certain circumstances with regard to their contractual obligations

In the dissenting opinion of The Mechanics' Bank of Alexandria v. Withers, Justice Story argued that the bank had a right to sue for payment on its debt as it was not barred by any statute or law from doing so. He further stated that if Congress intended to bar such suits, they would have done so explicitly in their legislation and thus should not be assumed without clear evidence. Additionally, he noted that there were no cases which supported this interpretation and therefore found it unjustified to deny the bank's claim against Withers based on an implied prohibition when none existed in either state or federal laws. Finally, Justice Story concluded by stating his belief that allowing banks to bring suit for debts due them was essential for maintaining public confidence in banking institutions and protecting creditors’ rights; thus denying these claims could lead to serious economic consequences throughout society at large.