In the case of Norfolk and Western Railway Co. v. Sims, the U.S Supreme Court ruled in favor of the railway company, reversing a decision by the Tennessee Supreme Court. The dispute arose when Mr. Sims was injured while working for Norfolk and Western Railway Company due to an alleged negligence on part of his employer's failure to provide safe equipment for work purposes. He sued under Tennessee law which allowed employees to sue employers directly instead of going through workers' compensation system if they could prove that their injuries were caused by intentional or negligent actions from their employers. The main issue before the court was whether federal laws governing interstate commerce superseded state laws allowing such lawsuits against railroads engaged in interstate commerce.The U.S Supreme Court held that federal law did indeed preempt state law in this context because it would interfere with uniformity necessary for smooth functioning of national transportation network if individual states had different rules regarding liability suits against railroad companies involved in interstate trade. Therefore, despite acknowledging potential validity of Mr.Sims' claim under Tennessee law,the court decided he should have pursued his claim via federally mandated channels i.e., through Federal Employers Liability Act (FELA),which provided specific procedures and remedies for railroad workers injured on job.

In the dissenting opinion for Norfolk and Western Railway Co. v. Sims, Justice Harlan argued that the majority's decision was inconsistent with previous rulings of the court regarding interstate commerce regulation. He contended that states should have authority to regulate rates charged by railroads within their borders unless Congress has specifically legislated on the matter or if state laws directly conflict with federal law. In this case, he believed neither condition had been met; thus, Tennessee’s law regulating intrastate railroad fares should not be invalidated simply because it may indirectly affect interstate commerce. Furthermore, he criticized the majority's reliance on hypothetical scenarios where state regulations could potentially interfere with interstate trade as a basis for striking down such laws preemptively without concrete evidence of actual interference.