The U.S. Supreme Court case Maricopa and Phoenix Railroad Company v. Arizona Territory in 1894 revolved around the issue of taxation on railroad companies operating within the territory of Arizona. The Maricopa and Phoenix Railroad Company argued that a tax levied by the territorial government was unconstitutional, as it violated their rights under both federal law and the Fourteenth Amendment's Equal Protection Clause due to its discriminatory nature against railroads compared to other forms of property or businesses. However, after reviewing the facts presented before them, including an examination into how taxes were assessed for different types of properties within Arizona at that time, the Supreme Court disagreed with this argument put forth by Maricopa & Phoenix Railroad Co., ruling instead in favor of Arizona Territory. They concluded that there was no evidence showing any intentional discrimination against railroads through these tax laws nor any violation of equal protection rights under constitutional law.

The dissenting opinion in the case of Maricopa and Phoenix Railroad Company v. Arizona Territory argued that the majority's decision to uphold a territorial law requiring railroads to maintain fences along their tracks was an overreach of judicial power. The dissent contended that this ruling effectively allowed courts to dictate how businesses should be run, which they believed was not within the purview of the judiciary. They also expressed concern about potential economic consequences, arguing that such regulations could discourage investment and hinder economic growth by imposing undue burdens on companies. Furthermore, they questioned whether it was fair or reasonable for railroads alone to bear all costs associated with fencing when other parties might also benefit from these structures.