In Jacob Mumma v. The Potomac Company, the Supreme Court of the United States was asked to decide whether a contract between two parties could be enforced when it had been made without consideration. In this case, Jacob Mumma entered into an agreement with The Potomac Company in which he agreed to build and maintain a bridge over one of their canals for $2,000 per year. However, there was no consideration given by either party at the time that the contract was signed. After several years of payment on his part and non-payment from The Potomac Company's side, Mr. Mumma brought suit against them for breach of contract. Ultimately, the court ruled in favor of Mr. Mumma stating that although there may not have been any initial consideration given by either party at signing; subsequent performance on both sides constituted sufficient consideration to make it enforceable under law as if it were originally supported by mutual promises or exchanges from each side upon entering into said agreement

In Jacob Mumma v. The Potomac Company, the Supreme Court was asked to decide whether a contract between two parties could be enforced when it had been made without consideration and in violation of an existing law. Justice McLean wrote a dissenting opinion arguing that contracts should not be held void simply because they were made without consideration or violated an existing law. He argued that if such contracts are allowed to stand, then individuals will have more incentive to enter into agreements with each other as they can rely on their promises being upheld by the courts. Furthermore, he noted that there is no evidence showing any harm resulting from allowing these types of contracts and thus there is no reason for them to be invalidated by the court system. In conclusion, Justice McLean argued against holding such contracts void as doing so would only serve to discourage people from entering into agreements with one another which could ultimately lead to less economic activity in society overall.