In New York v. Miln,48 decided in 1837, the relation of the States' police powers to the regulation of commerce was carefully considered. In this case a state law was upheld which required masters of all vessels arriving at the port of New York to make certain reports as to passengers carried, and imposed certain penalties in case this was not done. The opinion of the court was rendered by Justice Barbour. In this opinion it is declared that, "We shall not enter into any examination of the question whether the power to regulate commerce be or be not exclusive of the States, because the opinion which we have formed renders it unnecessary, in other words we are of opinion that the act is not a regulation of commerce, but of police, and that being thus considered, it was passed in the exercise of a power which rightfully belonged to the States."This police power is, however, so broadly defined, as in effect to give to the States a concurrent power of legislating with reference to matters subject to federal legislation. "Whilst a State is acting within the legitimate scope of its powers as to the end to be attained," the opinion declares, "it may use whatever means, being appropriate to that end, it may think fit; although they may be the same, or so nearly the same, as scarcely to be distinguishable from those adopted by Congress acting under a different power, subject only, say the court, to this limitation, that in the event of collision the law of the State must yield to the law of Congress. . . . Even then, if the section of the act J of the State] in question could be considered as partaking of the nature of a commercial regulation, the principle here laid down would save it from condemnation, if no such collision [with an act of Congress] exist."

From this language it is apparent that the test as to the validity of the state law is not as to the exclusiveness of the federal authority, but as to the existence of a countervailing act of Congress. In other words, the concurrent theory is, to this extent, adopted. In a dissenting opinion Justice Story argued strongly for the unconstitutionality of the state law and the exclusiveness of the federal authority and asserted that Marshall, before whom the case was first argued, had been in agreement with him. The existence of police powers in the States he admitted, but not that these powers might ever be used for the regulation of matters placed within the exclusive jurisdiction of the United States. "A State," he declared, "cannot make a regulation of commerce to enforce its health laws, because it is a means drawn from its authority. It may be admitted that it is a means adopted to the end, but it is quite a different question whether it be a means within the competency of the state jurisdiction."

48 11 Pet. 102; 9 L. ed. 648.