The case of Illinois Natural Gas Co. v. Central Illinois Public Service Co., et al., in 1941 involved a dispute over the right to supply natural gas to certain areas in Illinois. The plaintiff, Illinois Natural Gas Company (ING), had been granted permission by the Federal Power Commission (FPC) to construct and operate pipelines for this purpose, but was later challenged by Central Illinois Public Service Company who claimed that they already held exclusive rights under state law to serve these territories. ING argued that their federal permit preempted any conflicting state laws or regulations. The Supreme Court ruled in favor of ING, holding that when a company has received authorization from the FPC under the Natural Gas Act, it is not subject to competing claims based on state law or regulation regarding service territory boundaries. This decision affirmed the supremacy of federal authority in regulating interstate commerce involving natural gas distribution.

The dissenting opinion in the case of Illinois Natural Gas Co. v. Central Illinois Public Service Co., et al., argued that the majority's decision to uphold a state law requiring natural gas companies to obtain certificates of public convenience and necessity before constructing pipelines was an overreach of state power. The dissent contended that this requirement interfered with interstate commerce, which is under federal jurisdiction according to the Commerce Clause of the U.S Constitution. They believed that such regulation should be left up to federal authorities rather than individual states, as it could potentially disrupt or impede trade between states if each were allowed their own set of rules for pipeline construction. Furthermore, they expressed concern about potential harm caused by allowing states too much regulatory control over industries vital for national interests like energy production and distribution.