In the case of Southern Railway Company v. Postal Telegraph-Cable Company, 1900, the U.S Supreme Court was tasked with determining whether a telegraph company could be held liable for damages caused by its failure to deliver a message in a timely manner. The dispute arose when Southern Railway sent an urgent telegram via Postal Telegraph-Cable requesting repair materials after one of their trains derailed. Due to negligence on part of the telegraph operator, this message was not delivered promptly causing significant delay in repairs and subsequent financial loss for Southern Railway. The court ruled that while telegraph companies are indeed responsible for delivering messages accurately and promptly under normal circumstances, they cannot be held accountable if unforeseen events or conditions beyond their control prevent them from doing so. However, since it was proven that there were no such hindrances in this particular instance and that the delay occurred solely due to operator's negligence at Postal Telegraph-Cable Co., it was determined that they were liable for damages incurred by Southern Railway as a result of late delivery.

In the dissenting opinion for Southern Railway Company v. Postal Telegraph-Cable Company, Justice Harlan argued that the majority's decision was a departure from established principles of law and equity. He contended that it was not within the power of a railroad company to grant exclusive rights to one telegraph company over another on its right-of-way without express legislative authority. The granting of such exclusivity would be contrary to public policy as it could potentially hinder competition and limit service options available to consumers. Furthermore, he disagreed with the majority's interpretation of federal legislation regulating telegraph companies, arguing that Congress intended for these laws to promote competition rather than allow monopolies in this sector. Therefore, he believed that Postal Telegraph-Cable Company should have been allowed access along Southern Railway’s lines under reasonable terms.