In the 1949 case of Slocum v. Delaware, Lackawanna & Western Railroad Co., the U.S. Supreme Court ruled on a dispute between a railroad company and its telegraphers' union over whether certain work assignments constituted "overtime" under their collective bargaining agreement. The court held that this was an issue for arbitration rather than judicial determination, as provided by the Railway Labor Act (RLA). The RLA requires railroads and their employees to resolve minor disputes through binding arbitration before resorting to strikes or other forms of self-help. This decision reinforced the principle that courts should defer to arbitrators in interpreting collective bargaining agreements in industries governed by federal labor laws.

In the dissenting opinion for Slocum v. Delaware, Lackawanna & Western Railroad Co., Justice Robert H. Jackson argued that the majority's decision was a departure from established principles of labor law and collective bargaining rights. He contended that by allowing an employer to unilaterally change working conditions during negotiations, the Court undermined the balance of power between employers and employees intended by Congress in passing labor laws such as Railway Labor Act. Jackson emphasized that this imbalance could lead to industrial strife and unrest, which these laws were designed to prevent. Furthermore, he criticized the majority for interpreting contractual language too narrowly and ignoring its broader context within ongoing negotiations between parties.