HARVARD LA W REVIE W.
ates, to the extent of regulation, directly and immediately upon foreign or interstate commerce itself} If this rule is to be taken as established, there are certainly two exceptions. Inspection laws, saved by the Constitution itself,^ and quarantine laws are histori- cal exceptions, old as the Constitution itself, and recognized throughout the whole series of decisions construing it. The ques- tion left open by the Supreme Court in Henderson v. Mayor of New York,^ whether a State has power to exclude actual paupei immigrants or convicted criminals, must be considered doubtful, since the case of Bowman v, Chicago & N. W. R'y Co.^ A law excluding such persons would differ from a quarantine law by not being local and temporary in its operations ; so that the inaction of Congress might be construed in the one case as a regulation that no restraints shall be imposed, and not in the other.
We shall now consider the limitations imposed by the Constitu- tion upon the police power of the States, which are applicable to quarantine laws'. One limitation has already been considered, namely, that a State cannot impose a tonnage duty to defray quarantine expenses.* By far the most important limitation with which we have to deal is the power of Congress **to regulate com- merce with foreign nations, and among the several States." Quar- antine laws are, from their very nature, regulations of foreign and interstate commerce. It is practically impossible that the opera- tion of such laws should be confined to domestic commerce, whose entire transit is within the State.* In the language of Chief Jus- tice Marshall, constantly reiterated by the Supreme Court, " Com- merce undoubtedly is traffic, but it is something more, — it is intercourse."^ The case cited holds that commerce includes navi- gation. It has long been settled that persons as well as property are subjects of commerce in the sense of the Constitution.^ Quar- antine laws operate directly upon commerce itself, imposing re-
^It does not follow that all State legislation which indirectly regulates such com- merce is forbidden; for example, laws to prevent confusion among vessels, and to facili- tate the discharge of passengers and freight. See Gloucester Ferry Co. v. Penn., 114 U. S. 190, 206 (1884). Pilotage laws and port regulations seem to belong to this same class.
^ Const., art. i., sect. 10, cl. 2.
^ Const., art. i., sect. 10, cl. 3. See supra^ p. 269.
6 Compare Wabash Ry. Co, v. 111., 1 18 U. S. 558 (1886).
•Gibbons v, Ogden, 9 Wheat. I, 189 (1824).
' Gibbons r. Ogden, supra^ p. 215; Passenger Cases, 7 How. 283 (1849).