The chaos in judicial interpretation that characterized the TANEY COURT ' S COMMERCE CLAUSE cases was ended in Cooley, the most important decision on the subject between GIBBONS V. OGDEN (1824) and UNITED STATES V. E. C. KNIGHT CO. (1895). The Taney Court finally found a doctrinal formula that allowed a majority to coalesce around a single line of reasoning for the first time since the days of the MARSHALL COURT. That formula was the DOCTRINE of SELECTIVE EXCLUSIVENESS, announced for the majority by Justice BENJAMIN R. CURTIS. The doctrine was a compromise, combining aspects of the doctrines of CONCURRENT POWERS over commerce and EXCLUSIVE POWERS, but three Justices of the eight who participated rejected the compromise. Justices JOHN MCLEAN and JAMES M. WAYNE, whom Curtis privately called "high-toned Federalists," persisted
in their nationalist view, expressed in dissent, that congressional powers over INTERSTATE and FOREIGN COMMERCE were always exclusive, while PETER V. DANIEL, an intransigent states-rightist, concurred in the majority's result on the ground that congressional power over commerce was never exclusive.
At issue in Cooley was the constitutionality of a Pennsylvania statute requiring ships of a certain size entering or leaving the port of Philadelphia to employ local pilots in local waters. Cooley, claiming that the state act unconstitutionally regulated foreign commerce, refused to pay the pilotage fee. The fact that the first Congress had provided that the states could enact pilotage laws did not alter Cooley's claim. Curtis for the Court acknowledged that if the grant of commerce powers to Congress had divested the states of a power to legislate, the act of Congress could not confer that power on the states. The problem was whether the power of Congress in this case was exclusive.
Commerce, Curtis declared, embraces a vast field of many different subjects. Some subjects imperatively demand a single uniform rule for the whole nation, while others, like pilotage, demand diverse local rules to cope with varying local situations. The power of Congress was therefore selectively exclusive. If the subject required a single uniform rule, the states could not regulate that subject even in the absence of congressional legislation. In such a case congressional powers would be exclusive. Such was the nationalist half of the doctrine. The other half, by which the Court sustained the state act...