In Conley v. Nailor & Others, the Supreme Court of the United States was asked to decide whether a state court had the authority to issue an injunction against a railroad company that was operating in multiple states. The plaintiff, Conley, was a resident of the state of Illinois and had been injured in an accident involving a train owned by the defendant, Nailor & Others. Conley had sued the railroad company in an Illinois court, seeking damages for his injuries. The court had granted an injunction against the railroad company, ordering it to cease operations in Illinois until the case was resolved. The railroad company appealed the injunction to the Supreme Court, arguing that the state court did not have the authority to issue such an injunction against a company operating in multiple states. The Supreme Court disagreed, ruling that the state court had the authority to issue the injunction. The Court reasoned that the railroad company was subject to the laws of the state in which it operated, and that the state court had the authority to issue an injunction against the company in order to protect the rights of its citizens. The Court also noted that the injunction was necessary to ensure that the plaintiff was able to receive the compensation he was due for his injuries.

Justice Field delivered the dissenting opinion in Conley v. Nailor & Others, arguing that the majority had misapplied a prior Supreme Court decision and misinterpreted the relevant statute. He argued that under the plain language of both state law and federal statutes, it was clear that Congress intended to grant exclusive jurisdiction over such cases to state courts. Furthermore, he noted that while there were some exceptions for certain types of cases involving admiralty or maritime matters, this case did not fall into any of those categories and thus should have been heard by a state court rather than a federal one. Ultimately Justice Field concluded his dissent by noting that if Congress wanted to give exclusive jurisdiction over these kinds of cases to federal courts they would need to pass an explicit law doing so; otherwise it was up to each individual state's laws as written on how such disputes should be handled.