Final answer:
The requirement for pipeline owners to act as common carriers if there was service demand stems from the Supreme Court decision in Gibbons v. Ogden (1824), which established federal authority over interstate commerce and set a precedent against monopolistic practices.
Step-by-step explanation:
The Supreme Court judgment that resulted in the requirement for pipeline owners to act as common carriers if there was service demand was part of a series of decisions that defined the scope of national power concerning commerce. Specifically, the landmark decision Gibbons v. Ogden (1824) played a pivotal role in shaping future regulations of interstate commerce.
This case involved a dispute over steamboat ferry operations between New York and New Jersey, leading the Supreme Court to assert federal authority over interstate commerce and nullifying New York's attempt to grant a monopoly. This set a precedent that influences how common carrier laws are applied to various industries, including pipelines, to ensure they serve the public's needs without monopolistic practices.