January 14, 1878, Decided; OCTOBER, 1877 Term

MR. CHIEF JUSTICE WAITE delivered the opinion of the court.

For the purposes of this case, we must treat the act of Louisiana of Feb. 23, 1869, as requiring those engaged in inter-state commerce to give all persons traveling in that State, upon the public conveyances employed in such business, equal rights and privileges in all parts of the conveyance, without distinction or discrimination on account of race or color. Such was the construction given to that act in the courts below, and it is conclusive upon us as the construction of a State law by the State courts. It is with this provision of the statute alone that we have to deal. We have nothing whatever to do with it as a regulation of internal commerce, or as affecting any thing else than commerce among the States.

There can be no doubt but that exclusive power has been conferred upon Congress in respect to the regulation of commerce among the several States. The difficulty has never been as to the existence of this power, but as to what is to be deemed an encroachment upon it; for, as has been often said, legislation may in a great variety of ways affect commerce and persons engaged in it without constituting a regulation of it within the meaning of the Constitution. Sherlock v. Alling, 93 U.S. 103; State Tax on Railway Gross Receipts, 15 Wall. 284. Thus, in Munn v. Illinois, 94 U.S. 113, it was decided that a State might regulate the charges of public warehouses, and in Chicago, Burlington, & Quincy Railroad Co. v. Iowa, id. 155, of railroads situate entirely within the State, even though those engaged in commerce among the States might sometimes use the warehouses or the railroads in the prosecution of their business. So, too, it has been held that States may authorize the construction of dams and bridges across navigable streams situate entirely within their respective jurisdictions. Willson v. Blackbird Creek Marsh Co., 2 Pet. 245; Pound v. Turck, supra, p. 459; Gilman v. Philadelphia, 3 Wall. 713. The