In the 1940 case of Jenkins v. Kurn et al., Trustee, the U.S. Supreme Court ruled on a matter involving an employee's injury while working for a railroad company that operated in multiple states. The plaintiff, Jenkins, was injured in Missouri but filed his claim under the Federal Employers' Liability Act (FELA) in Illinois because he believed it would be more favorable to him due to differences between state laws regarding contributory negligence and assumption of risk defenses available to employers. The defendants argued that Missouri law should apply as this is where the incident occurred and they were headquartered there; however, FELA did not specify which state’s law should govern such cases. The Supreme Court held that federal common law governed questions about liability under FELA regardless of where suit was brought or accident occurred - thus rejecting application of any specific state's laws over another when dealing with interstate commerce issues like these. This decision clarified jurisdictional matters related to lawsuits arising from injuries sustained by employees engaged in interstate commerce activities.

In the dissenting opinion for Jenkins v. Kurn et al., Trustee, Justice Frank Murphy disagreed with the majority's ruling that a railroad company could be held liable for injuries sustained by an employee who was struck by a train while walking along tracks not owned or operated by his employer. He argued that under the Federal Employers' Liability Act (FELA), liability should only apply when there is negligence on part of the employer and if such negligence played any part in causing injury to its employees. In this case, he contended that no evidence had been presented showing any negligent act committed by the defendant which contributed to plaintiff’s injury. Furthermore, he pointed out that it was common practice for railway workers to use tracks as walkways and thus it would be unreasonable to hold employers responsible every time an accident occurred under these circumstances without clear proof of their negligence contributing directly towards such accidents.