In the 1943 case Tennant v. Peoria & Pekin Union Railway Co., the U.S Supreme Court ruled in favor of the railway company, overturning a decision by an Illinois state court that had awarded damages to Mrs. Tennant for her husband's death in a train accident. The central issue was whether or not Mr. Tennant, who was employed as a switchman and brakeman by another railroad company but working on tracks owned by Peoria & Pekin Union Railway at the time of his fatal accident, could be considered an employee of both companies under federal law - specifically, under the Federal Employers' Liability Act (FELA). The Supreme Court held that he could not be considered an employee of both companies simultaneously for purposes of FELA liability; therefore, since he was acting within his duties to his actual employer when killed and wasn't performing any services for Peoria & Pekin Union Railway at that moment, this latter entity couldn't be held liable for his death.

In the dissenting opinion for Tennant v. Peoria & Pekin Union Railway Co., Justice Frank Murphy argued that the majority's decision was a departure from established principles of negligence law, which traditionally held employers responsible for providing safe working conditions. He contended that by ruling in favor of the railway company, despite evidence suggesting it had failed to provide adequate safety measures, the court was effectively absolving employers from their duty to protect workers' lives and limbs. Furthermore, he criticized his colleagues for ignoring substantial evidence showing that Mrs. Tennant's husband died as a result of unsafe work conditions on defendant’s premises and not due to an unforeseeable accident or his own carelessness. In essence, Justice Murphy believed this case represented a dangerous shift towards prioritizing corporate interests over worker safety.