Union Pacific Railroad v. Cloppper was a case heard by the United States Supreme Court in which the Court held that a railroad company was not liable for damages caused by a train accident due to the negligence of its employees. The case arose when a train operated by the Union Pacific Railroad collided with a wagon driven by Cloppper, resulting in the death of Cloppper's horse. Cloppper sued the railroad for damages, arguing that the railroad was liable for the negligence of its employees. The Supreme Court held that the railroad was not liable for the accident. The Court reasoned that the railroad was not liable because the negligence of its employees was not foreseeable. The Court noted that the railroad had taken reasonable steps to ensure the safety of its passengers and that the accident was caused by an unexpected event. The Court also noted that the railroad had not been negligent in its operation of the train. The Court's decision in Union Pacific Railroad v. Cloppper established that a railroad company is not liable for damages caused by a train accident due to the negligence of its employees if the negligence was not foreseeable. The Court's decision has been cited in numerous cases since then, and it remains an important precedent in the area of railroad liability.

In Union Pacific Railroad v. Cloppper, the Supreme Court was asked to decide whether a railroad company could be held liable for damages caused by its negligence in failing to properly maintain and inspect its tracks. The majority opinion found that the railroad had acted negligently and should be held liable for any resulting damage or injury; however, Justice Field dissented from this decision. He argued that while it is true that railroads have a duty of care towards their passengers, they are not required to guarantee absolute safety on their lines at all times due to the inherent risks associated with railway travel. Furthermore, he noted that Congress had already enacted legislation which limited liability in such cases and thus there was no need for further judicial action on this matter. Ultimately, Justice Field concluded that holding railroads strictly liable would impose an undue burden upon them without providing any additional benefit or protection against harm for travelers using their services