Ruch v. Rock Island was a United States Supreme Court case that dealt with the issue of whether a railroad company was liable for damages caused by a train accident. The plaintiff, Ruch, was a passenger on a train operated by the defendant, Rock Island Railroad Company. The train derailed, causing Ruch to suffer serious injuries. Ruch sued the railroad company, claiming that the accident was caused by the company's negligence. The Supreme Court held that the railroad company was liable for the damages caused by the accident. The Court found that the company had a duty to exercise reasonable care in the operation of its trains, and that it had breached that duty by failing to properly maintain the tracks. The Court also held that the company was liable for the damages caused by the accident, even though the company had not been negligent in the operation of the train itself. The Court's decision in Ruch v. Rock Island established that railroad companies are liable for damages caused by their negligence, even if the negligence is not related to the operation of the train itself. This decision has been cited in numerous subsequent cases involving railroad companies and their liability for damages caused by their negligence.

In Ruch v. Rock Island, the Supreme Court was asked to decide whether a contract between two parties that had been partially performed could be enforced by one of the parties against the other. The majority opinion held that it could not, as there was no consideration for such an agreement and thus it lacked mutuality of obligation. Justice Field dissented from this decision on the grounds that partial performance should be sufficient consideration in cases where both parties have received some benefit from their arrangement and are mutually obligated to fulfill its terms. He argued that if a party has already begun performing under an agreement, then they should not be allowed to back out without any consequence or penalty; rather, they should still remain liable for fulfilling their part of the bargain even if only partial performance has occurred up until then.