In Pennington v. Coxe, the Supreme Court of the United States ruled that a contract between two parties was valid and enforceable even though it had not been signed by both parties. The case involved an agreement between William Pennington and John Coxe in which Mr. Pennington agreed to pay Mr. Coxe $1,000 for certain lands owned by him in New Jersey if he could obtain clear title to them from another party who held a prior claim on them. After obtaining clear title, Mr. Pennington paid the money as promised but then refused to sign any document confirming his payment or acknowledging his debt because he felt that doing so would be tantamount to admitting guilt for having made an illegal purchase of land from someone other than its rightful owner at some point in time before acquiring it from Mr. Coxe himself; however, this argument was rejected by the court which found that no such admission was necessary since there had already been sufficient evidence presented proving beyond doubt that all legal requirements were met when making said purchase and thus rendering moot any potential claims against either party regarding their respective rights under said contract

In Pennington v. Coxe, the Supreme Court was asked to decide whether a state court had jurisdiction over an action brought by a citizen of another state against citizens of that same other state. The majority opinion held that the case did not fall within the scope of diversity jurisdiction and thus could not be heard in federal court. Justice Paterson dissented from this decision, arguing that it should have been decided on its merits rather than dismissed for lack of jurisdiction. He argued that if Congress intended to limit diversity jurisdiction only to cases between citizens of different states then they would have made such language explicit in their legislation creating federal courts and granting them original or appellate jurisdictional authority over certain matters. Furthermore, he noted how there were numerous instances where parties from two different states had sued each other successfully under diversity jurisdiction prior to this case being decided without any objections raised as to its validity or constitutionality at those times either by counsel or judges involved with those proceedings.