Southern Pacific Co. v. Arizona

By the time the Southern Pacific Company and the state of Arizona squared off before the U.S. Supreme Court, the two sides had been battling before courts for 15 years. The germ of the controversy lay within a 1912 Arizona law prohibiting operation of railroad trains of more than 14 passenger cars or 70 freight cars within the state. At the time it was passed, the law was uncontroversial because it reflected a relatively standard train length. As track systems were modernized and stronger locomotives appeared, the Arizona limit became a nuisance to the Southern Pacific Company. The railroad found that it had to stop and shorten its freight trains at terminals near the New Mexico and California borders in order to pass through Arizona without being heavily fined. It was only a matter of time before the issue landed in court.

In 1939, after ten years of unsuccessful preliminary legal skirmishes, the Southern Pacific Company filed suit against Arizona Attorney General Joe Conway, asking a federal court to declare that the Train Limit Law was unconstitutional. In an unusual legal maneuver, Conway ignored the suit. The court dismissed the case, since no controversy appeared to exist for it to adjudicate. When Southern Pacific began to run long trains through the state, however, the railroad forced Conway's hand. He filed suit against Southern Pacific in April of 1940 for violating the Train Limit Law. In its defense, the railroad responded by attacking the constitutionality of the law.

After months of exhaustive hearings, the railroad convinced the Pima County Court that longer trains were safer and less financially burdensome than those operating under the limit law. Conway quickly appealed the case to the Arizona Supreme Court. This time, the state law was interpreted to be valid. On 23 December 1943, the Arizona Supreme Court reversed the county court's judgment and found the railroad liable for fines due to violation of the Train Limit Law.