In M'Iver and Others v. Wattles, the Supreme Court of the United States ruled that a contract between two parties must be executed in good faith and with reasonable diligence to be valid. The case involved a dispute over land ownership between William Wattles and several other individuals who had purchased land from him. The plaintiffs argued that they had paid for their purchase but were never given title to the property because Wattles failed to execute his part of the agreement in good faith or with reasonable diligence. In its ruling, the court held that contracts are binding only when both parties fulfill their obligations under it; if one party fails to do so, then any rights granted by such an agreement become voidable at law. Furthermore, it was determined that even though there may have been no fraud on either side of this particular transaction, due to lack of performance by one party (Wattles), he could not enforce his claim against them as he did not act according to what was agreed upon in good faith or with reasonable diligence.

In M'Iver and Others v. Wattles, the Supreme Court was asked to decide whether a state court had jurisdiction over a case involving citizens of different states. The majority opinion held that it did not have such jurisdiction because the Constitution does not grant any power to state courts in cases between citizens of different states. However, Justice Johnson dissented from this decision on the grounds that Congress has exclusive authority over interstate disputes and should be allowed to determine which court has jurisdiction in these matters. He argued that allowing each state's courts to exercise their own discretion would lead to confusion and uncertainty as well as unequal treatment for litigants depending on where they lived or brought suit. Furthermore, he believed that if Congress were given exclusive authority then uniformity could be achieved across all jurisdictions while still protecting individual rights under the law.