In Sands v. Knox, the Supreme Court of the United States was asked to decide whether a state court had jurisdiction over a case involving citizens from different states. The plaintiff, John Sands, sued William Knox in Massachusetts for breach of contract and sought damages for goods that were not delivered as promised. Knox argued that he should be tried in his home state of New York because it was where the contract originated and where he resided at the time of suit. The Supreme Court held that since both parties were citizens from different states, then federal courts had exclusive jurisdiction over such cases under Article III Section 2 Clause 1 of the Constitution which grants original jurisdiction to federal courts when one party is an alien or citizen from another state than their own. This ruling established precedent for future cases regarding diversity jurisdiction between two parties with diverse citizenship status within America's judicial system.

In the case of Sands v. Knox, Chief Justice John Marshall wrote a dissenting opinion in which he argued that the court should not have dismissed the plaintiff's claim for damages due to an alleged breach of contract. He reasoned that although there was no written agreement between the parties, it could be inferred from their conduct and correspondence that they had entered into a binding agreement. Furthermore, he noted that even if there were some ambiguity as to whether or not an enforceable contract existed, this should have been decided by a jury rather than by summary judgment on behalf of either party. In conclusion, Chief Justice Marshall believed that since both parties had acted in reliance upon each other’s promises and assurances regarding payment for goods delivered and services rendered, justice would best be served if their dispute was heard before a jury who could determine whether or not any contractual obligations actually existed between them.