In Singleton v. Touchard, the Supreme Court of the United States was tasked with determining whether a state court had jurisdiction to hear a case involving an action brought by citizens of one state against citizens of another state in which all parties were non-residents. The plaintiff argued that since he and his co-plaintiffs were not residents of either party's home states, they should be allowed to bring their suit in any court within the Union. The defendant argued that this would violate principles established under Article III Section 2 Clause 1 (the "diversity clause") which grants exclusive jurisdiction over such cases to federal courts when there is complete diversity between parties from different states. After considering both sides' arguments, the Court held that while it may have been possible for Congress to grant concurrent jurisdiction over these types of cases between federal and state courts, no such legislation existed at the time and thus only federal courts could exercise authority over them due solely to diversity issues.

In Singleton v. Toucheard, 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 the state court did not have jurisdiction because it violated Article III of the Constitution, which grants exclusive original jurisdiction to federal courts in cases between citizens of different states. Justice Grier dissented from this decision and argued that while Article III does grant exclusive original jurisdiction to federal courts in such cases, Congress has authority under Section 2 of Article IV to give concurrent or supplemental powers to state courts when necessary for public justice and convenience. He further noted that Congress had done so with respect to diversity suits by passing several statutes granting power over such matters as admiralty claims and patent disputes; thus he concluded that there is no reason why they could not do so here as well if they chose.