In the case of South Buffalo Railway Co. v. Ahern et al., 1952, the U.S Supreme Court ruled in favor of South Buffalo Railway Company, reversing a decision made by New York's highest court. The dispute involved an injury claim filed by John J. Ahern who was employed as a switchman for the railway company and got injured while performing his duties on an interstate train within New York State boundaries. He sought compensation under Federal Employers' Liability Act (FELA). However, South Buffalo Railway argued that since it was not engaged in interstate commerce at that time but only intrastate activities, FELA did not apply to them. The Supreme Court held that even though the specific task performed by Mr.Ahern at the time of his injury was related to intrastate commerce, because he was generally involved in tasks contributing to both intra- and inter-state commerce during his employment with South Buffalo Railway - which itself is part of a larger network facilitating interstate trade - FELA could be applied here.

The dissenting opinion in the case of South Buffalo Railway Co. v. Ahern et al., 1952, argued that the majority's decision to uphold a state law requiring railroads to pay for protective barriers at highway crossings was an overreach of federal power and infringed upon states' rights. The dissenters believed that this issue should be left up to individual states rather than being federally mandated, as it pertains more directly to local safety concerns and infrastructure needs rather than interstate commerce or national security issues. They also expressed concern about setting a precedent where federal courts could interfere with state laws regarding public utilities regulation, potentially leading to further erosion of states' powers in future cases.