Dennison v. Alexander was a United States Supreme Court case that addressed the issue of whether a state court could enforce a contract that was made in another state. The case involved a contract between two parties, Dennison and Alexander, in which Dennison agreed to pay Alexander a certain sum of money in exchange for Alexander's services. The contract was made in the state of New York, but Alexander sued Dennison in a court in the state of Ohio. The Supreme Court held that the Ohio court had no jurisdiction to enforce the contract because it was made in another state. The Court reasoned that the contract was made in New York and was therefore subject to the laws of that state. The Court also noted that the Ohio court had no authority to enforce the contract because it was not made in Ohio. The Court's decision in Dennison v. Alexander established the principle that a state court cannot enforce a contract that was made in another state. This principle is still followed today and is an important part of the law of contracts.

In Dennison v. Alexander, the Supreme Court was asked to decide whether a contract between two parties could be enforced when one of them had died before it was completed. The majority opinion held that the contract could not be enforced because it had not been fully executed by both parties prior to death and thus did not meet all of the requirements for enforceability under state law. Justice Field dissented from this decision, arguing that there were no legal grounds preventing enforcement of such contracts in cases where only one party has passed away before completion. He argued that if a contract is validly entered into with full knowledge and consent on both sides, then its terms should still remain binding even after one party's death; otherwise, people would have little incentive to enter into any kind of contractual agreement knowing they can never rely on its enforcement afterwards due to unforeseen circumstances like death or illness.