In the case of Western Union Telegraph Company v. Pennsylvania Railroad Company et al., 1904, the U.S Supreme Court was tasked with determining whether a contract between Western Union and several railroad companies violated antitrust laws. The agreement in question allowed Western Union to install telegraph lines along railway tracks owned by these companies, in exchange for free telegrams and a share of profits from commercial messages sent over these wires. Competing telegraph firms argued that this arrangement constituted an illegal monopoly. The court ruled in favor of Western Union, stating that while such contracts could potentially be used to create monopolies or stifle competition, they were not inherently anti-competitive or unlawful under the Sherman Antitrust Act. The justices reasoned that since railroads had no inherent advantage in providing telegraph services and other firms were free to negotiate similar agreements with them if they wished, there was no violation of antitrust law.

In the dissenting opinion for Western Union Telegraph Company v. Pennsylvania Railroad Company, Justice Harlan disagreed with the majority's decision that Western Union was not liable to pay taxes on telegraph poles and wires located along public highways in Pennsylvania. He argued that these properties were indeed real estate as they were permanently affixed to the ground and used for profit-making purposes by the company. Furthermore, he contended that just because a corporation has been granted certain privileges or immunities by a state does not mean it is exempt from paying its fair share of taxes like any other property owner within said state. Therefore, according to Justice Harlan, such tax exemptions should be explicitly stated in legislation rather than being assumed or inferred based on vague legal interpretations.