280 ^^R VARD LA W RE VIE W.
within the meaning of the Constitution." ^ Whether a certain law regulates or only affects commerce is sometimes as difficult to determine as whether a given cause of damage was proximate or remote ; yet the distinction is legally as real and necessary in the one case as the other. No sharp dividing line can be drawn where the gradations are so indefinite.
When, however, we come to consider the use of the words *' reg- ulation of commerce" as applied to State legislation, we find dif- ferent meanings, due to past conflicting theories of constitutional rights. Until the question was settled whether the power of Con- gress to regulate foreign and interstate commerce was exclusive, or whether a like concurrent power belonged to the States, the advocates of the doctrine of absolute exclusiveness were compeUed to maintain that all regulations of such commerce by the States were unconstitutional. When, therefore, they said a State law was a regulation of foreign or interstate commerce, they implied that the law was not constitutional. Now, certain State police regulations obstructing commerce — such as quarantine laws — were conceded by all to be constitutional. It had, therefore, to be assumed by those judges who maintained the theory of exclusive- ness that a police regulation could not be a regulation of commerce, — a proposition which, as we have seen, was found serviceable in sustaining the laws of the slave States excluding free negroes. The result was a use of the term " regulation of commerce " which led to no little confusion. The first case in which the clause grant- ing to Congress power to regulate commerce was construed was Gibbons v, Ogden.^ There the court held that a law of New York granting for a term of years to Robert Fulton and another the exclusive right of navigating with boats moved by fire or steam all waters within the jurisdiction of the State, was unconstitutional, so far as the law applied to vessels licensed under the laws of the United States to carry on coasting-trade. Illustrations of the use of the words ** regulation of commerce " in a sense excluding po- lice regulations, will be found in the arguments of Mr. Webster ^ and Mr. Wirt,* as well as the opinion of Chief Justice Marshall^ and Mr. Justice Johnson.^ Mr. Oakley's argument, however, intimates that police regulations may be also regulations of com-
1 Sherlock v. Ailing, 93 U. S. 99, 103 (1876).
89 Wheat. I (1824).
• 9 Wheat, 18. * lb, p. 1 78. » lb, p. 203. « lb, p. 255.