The Brotherhood of Railroad Trainmen v. Chicago River & Indiana Railroad Co., 1956, was a U.S Supreme Court case that revolved around the issue of whether or not labor unions could provide legal assistance to their members in personal injury cases without violating state laws prohibiting non-lawyers from practicing law. The court ruled in favor of the Brotherhood of Railroad Trainmen, stating that it was within their First Amendment rights to advise and refer union members to lawyers for litigation purposes. This decision established an important precedent regarding the role and rights of labor unions in providing support services for their members beyond collective bargaining.

In the dissenting opinion for Brotherhood of Railroad Trainmen et al. v. Chicago River & Indiana Railroad Co. et al., Justice Frankfurter argued that the majority's decision to allow union members to solicit legal representation on behalf of injured workers was a violation of state laws prohibiting non-lawyers from engaging in activities considered as practicing law, such as solicitation and negotiation with attorneys. He contended that this ruling could potentially lead to abuses by unions who might use their position to pressure or manipulate workers into choosing certain lawyers or taking specific legal actions beneficial for the union rather than individual worker's interests. Furthermore, he expressed concern over potential conflicts between federal labor policy and state regulation of professional conduct within its jurisdiction which may arise due to this ruling.