
84 U.S. 560 (1873)
17 Wall. 560
RAILROAD COMPANY
v.
FULLER.
Supreme Court of United States.

*562 Messrs. H.C. Henderson and B.C. Cook, for the plaintiff in error.
Messrs. J. Hubley Ashton and N. Wilson, contra.
*566 Mr. Justice SWAYNE delivered the opinion of the court.
The case lies within a narrow compass, and presents but a single question for our consideration. That question is not difficult of solution. The second section, chapter 169, of the laws of the ninth General Assembly of Iowa is as follows:
"In the month of September, annually, each railroad company shall fix its rates of fare for passengers and freight, for transportation of timber, wood, and coal per ton, cord, or thousand feet, per mile; also, its fare and freight per mile for transporting merchandise and articles of the first, second, third, and fourth grades of freight; and on the first day of October following shall put up at all stations and depots on its road a printed copy of such fare and freight, and cause a copy to remain posted during the year. For wilfully neglecting so to do, or for receiving higher rates of fare or freight than those posted, the company shall forfeit not less than one hundred dollars nor more than two hundred dollars to any person injured thereby and suing therefor."
The plaintiff in error was sued in the proper District Court of the State for violations of these provisions. Among other defences interposed, the company plead that the statute was in conflict with the commercial clause of the Constitution *567 of the United States. Fuller demurred to the plea. The court sustained the demurrer and the company excepted. The case was afterwards submitted to a jury. The company prayed the court to instruct them that the act was invalid by reason of the conflict before mentioned. The court refused, and the company again excepted. A verdict and judgment were rendered for the plaintiff. The company removed the case to the Supreme Court of the State, and there insisted upon these exceptions as errors. That court affirmed the judgment of the District Court, and the company thereupon prosecuted this writ of error. Was there error in this ruling?
The Constitution gives to Congress the power "to regulate commerce with foreign nations, and among the several States, and with the Indian tribes."
The statute complained of provides 
That each railroad company shall, in the month of September, annually, fix its rates for the transportation of passengers and of freights of different kinds;
That it shall cause a printed copy of such rates to be put up at all its stations and depots, and cause a copy to remain posted during the year;
That a failure to fulfil these requirements, or the charging of a higher rate than is posted, shall subject the offending company to the payment of the penalty prescribed.
In all other respects there is no interference. No other constraint is imposed. Except in these particulars the company may exercise all its faculties as it shall deem proper. No discrimination is made between local and interstate freights, and no attempt is made to control the rates that may be charged. It is only required that the rates shall be fixed, made public, and honestly adhered to. In this there is nothing unreasonable or onerous. The public welfare is promoted without wrong or injury to the company. The statute was doubtless deemed to be called for by the interests of the community to be affected by it, and it rests upon a solid foundation of reason and justice.
*568 It is not, in the sense of the Constitution, in any wise a regulation of commerce. It is a police regulation, and as such forms "a portion of the immense mass of legislation which embraces everything within the territory of a State not surrendered to the General Government, all which can be most advantageously exercised by the States themselves."[*]
This case presents a striking analogy to a prominent feature in the case of The Brig James Gray v. The Ship John Fraser.[] There the city authorities of Charleston had passed an ordinance prescribing where a vessel should lie in the harbor, what light she should show at night, and making other similar regulations. It was objected that these requirements were regulations of commerce and, therefore, void. This court affirmed the validity of the ordinance.
In the complex system of polity which exists in this country the powers of government may be divided into four classes:
Those which belong exclusively to the States.
Those which belong exclusively to the National Government.
Those which may be exercised concurrently and independently by both.
And those which may be exercised by the States but only until Congress shall see fit to act upon the subject.
The authority of the State then retires and lies in abeyance until the occasion for its exercise shall recur.[]
Commerce is traffic, but it is much more. It embraces also transportation by land and water, and all the means and appliances necessarily employed in carrying it on.[§]
The authority to regulate commerce, lodged by the Constitution in Congress, is in part within the last division of the powers of government above mentioned. Some of the rules prescribed in the exercise of that power must from the nature of things be uniform throughout the country. To *569 that extent the authority itself must necessarily be exclusive, as much so as if it had been declared so to be by the Constitution in express terms.
Others may well vary with the varying circumstances of different localities. Where a stream navigable for the purposes of foreign or interstate commerce is obstructed by the authority of a State, such exercise of authority may be valid until Congress shall see fit to intervene. The authority of Congress in such cases is paramount and absolute, and it may compel the abatement of the obstruction whenever it shall deem it proper to do so. A few of the cases illustrating these views will be adverted to.
In Willson v. The Blackbird Creek Marsh Company,[*] under a law of the State of Delaware, a dam had been erected across the creek. This court held that the dam was a lawful structure, because not in conflict with any law of Congress.
In Gilman v. The City of Philadelphia,[] the State of Pennsylvania had authorized the erection of a bridge over the Schuylkill River, in the city of Philadelphia. This court refused to interpose, because there was no legislation by Congress affecting the river. The authority of Congress over the subject was affirmed in the strongest terms.
In The Wheeling Bridge Case,[] the bridge was decreed to be a nuisance, because Congress "had regulated the Ohio River, and had thereby secured to the public the free and unobstructed use of the same." Congress subsequently legalized the bridge, and this court held the case to be thereby terminated.
In Cooley v. The Board of Wardens,[§] the validity of a State law establishing certain pilotage regulations, was drawn in question. It was admitted by this court that the regulations were regulations of commerce, but it was held that they were valid and would continue to be so until superseded by the action of Congress.
In Ex parte McNiel,[] the same question arose, and the doctrine of the preceding case was reaffirmed.
*570 In The James Gray v. The John Fraser,[*] stress was laid upon the fact that there was no act of Congress in conflict with the city ordinance in question. See, also, in this connection, Osborne v. The City of Mobile.[]
If the requirements of the statute here in question were, as contended by the counsel for the plaintiff in error, regulations of commerce, the question would arise, whether, regarded in the light of the authorities referred to, and of reason and principle, they are not regulations of such a character as to be valid until superseded by the paramount action of Congress. But as we are unanimously of the opinion that they are merely police regulations, it is unnecessary to pursue the subject.
JUDGMENT AFFIRMED.
NOTES
[*]  Gibbons v. Ogden, 9 Wheaton, 1.
[]  21 Howard, 184.
[]  Ex parte McNiel, 13 Wallace, 240.
[§]  2 Story on the Constitution, §§ 1061, 1062.
[*]  2 Peters, 250.
[]  3 Wallace, 728.
[]  18 Howard, 430.
[§]  12 Howard, 319.
[]  Supra.
[*]  21 Howard, 184.
[]  16 Wallace, 479.
