Cooley  v. The Board of Wardens of the Port of Philadelphia, 12 Howard (53 U.S.) 299; 13 L. Ed. 996 (1851)

Facts—The Board of Wardens of the port of Philadelphia, acting under a statute of the state of Pennsylvania that established an elaborate system of regulations regarding pilots in the port including monetary penalties for failure to comply with the regulations, attempted to enforce the regulations. Cooley violated the regulations and when tried alleged that they were unconstitutional.

Issue—Does congressional power to regulate interstate commerce preclude all state pilotage regulations?

Decision—J. Curtis (6–2). The grant of power to regulate commerce does not contain any terms that expressly exclude the states from exercising any authority over this subject matter. Although Congress has the power to regulate pilots, its legislation manifests an intention to allow states to regulate in this area. Curtis observed that “the power to regulate commerce, embraces a vast field, containing not only many, but exceedingly various subjects, quite unlike in their nature; some imperatively demanding a single uniform rule, operating equally on the commerce of the United States in every port; and some, like the subject now in question, as imperatively demanding that diversity, which alone can meet the local necessities of navigation.” J. McLean and J. Wayne dissented.

Note—The Court adopted a “selective exclusiveness doctrine” in which Congress would regulate commerce that was national and uniform, and the states would regulate such matters that were considered to be local.