In the 1969 case of Detroit & Toledo Shore Line Railroad Co. v. United Transportation Union et al., the U.S Supreme Court ruled in favor of the railroad company, stating that a dispute over whether or not to include a union shop agreement in collective bargaining was minor and should be resolved through arbitration as per Railway Labor Act (RLA). The United Transportation Union had sought to enforce such an agreement, which would require all employees to join their union after a certain period of employment. However, the railroad company argued this was not mandatory under existing contracts and laws. The court agreed with them based on RLA's purpose - preventing work stoppages in public transportation industries by mandating negotiation or arbitration for disputes.

In the dissenting opinion for Detroit & Toledo Shore Line Railroad Co. v. United Transportation Union et al., Justice Harlan disagreed with the majority's interpretation of the Railway Labor Act (RLA). He argued that Congress intended to limit federal courts' jurisdiction over minor disputes in order to encourage resolution through negotiation and arbitration, not litigation. The RLA was designed to promote collective bargaining and minimize work stoppages, not provide a platform for judicial intervention in labor disputes. By allowing federal courts to intervene prematurely, he believed that it would undermine these goals by discouraging negotiation and encouraging parties to seek court intervention instead of resolving their differences amicably or through established dispute resolution procedures under the RLA.