In the 1957 case of Sinkler v. Missouri Pacific Railroad Co., the U.S. Supreme Court ruled in favor of an African American railroad worker, Ernest Sinkler, who was injured while working for the Missouri Pacific Railroad Company. The court held that under the Federal Employers' Liability Act (FELA), a railroad company could be held liable for injuries to its employees caused by negligence on part of any other employee within the scope of their employment, regardless if they were immediate supervisors or not. This ruling overturned lower courts’ decisions which had dismissed Sinkler's claim based on grounds that his injury was caused by a co-worker and not directly by his employer. The decision expanded protections for workers under FELA and clarified employers' responsibilities towards ensuring safety at workplaces.

In the dissenting opinion for Sinkler v. Missouri Pacific Railroad Co., Justice Frankfurter argued that the majority's interpretation of the Federal Employers' Liability Act (FELA) was too broad and inconsistent with its legislative history. He contended that Congress intended FELA to apply only when an employee's injury resulted from negligence by another employee who was also engaged in interstate commerce, not simply because the employer is involved in such commerce. The justice believed this narrower interpretation would better align with Congress’s intent to regulate safety conditions specifically related to interstate railroads rather than all aspects of railroad employment. Furthermore, he criticized the majority for creating a new standard of liability without clear statutory basis or precedent, which could potentially lead to unpredictable and unfair results.