after making the foregoing statement,, delivered the opinion of the court.

The single question is one of constitutionality. Has Congress power to punish the offense charged, or is jurisdiction thereover solely with the State? Undoubtedly, as held, “Congress has the power to exclude aliens from the United States; to prescribe the terms and conditions on which they may come .in; to establish regulations for.sending out of the country such aliens as have entered in violation of law, "and to commit the enforcement -of such conditions and regulations to executivé *144officers.” Turner v. Williams, 194 U. S. 279, 289. See also Fong Yue Ting v. United States, 149 U. S. 698, 708; Head Money Cases, 112 U. S. 580, 591; Lees v. United States, 150 U. S. 476, 480, United States v. Bitty, 208 U. S. 393.

It is unnecessary to determine how fat Congress may go in legislating .With respect to the conduct of an alien while residing here, for there is no charge against one; nor to prescribe the extent of its power in punishing wrongs done to an alien, for there is neither charge nor proof of any such wrong. So far as the statuteor the indictment requires, or the testimony shows, she was ^voluntarily living the life of a prostitute, and was only furnished a place by the defendants to follow her degraded life, . While the keeping of a house of ill-fame is offensive to the, moral sense, yet that fact must not close the eye to the question whether the power to punish therefor is. delegated to Congress or is reserved to the State. Jurisdiction over such an'offense comes within the accepted definition of the police power. Speaking generally, that power is reserved to" the States," fot there is in the Constitution no grant thereof to Congress, i

In Patterson v. Kentucky, 97 U. S. 501, 503, is this declaration:

“ ‘In the American constitutional system/ says Mr. Cooley, ‘the power to establish the ordinary regulations of police has been left with the individual States, and cannot be assumed by the national government.’ Cooley, Const. Lim.- 574. While it is confessedly difficult to mark the precise boundaries of that power, or to indicate, by any general rule, the exact limitations which the States must observe in its exercise, the existence; of such a power in the States has been uniformly recognized in this court. Gibbons v. Ogden, 9 Wheat. 1; License Cases, 5 How. 504; Gilman v. Philadelphia, 3 Wall. 713; Henderson v. Mayor of the City of New York, 92 U. S. 259; Railroad Company v. Husen, 95 U. S. 465; Beer Company v. Massachusetts, 97 U. S. 25. It is embraced in what Mr.. Chief Justice Marshall in Gibbons v. Ogden, calls that ‘immense mass *145of .legislation/ which can be most advantageously exercised by the States, and over which the national authorities cannot assume supervision or control.”.

And in Barbier v. Connolly, 113 U. S. 27, 31, it is said:

“But neither the amendment — broad and comprehensive as it is — nor any other amendment, was'designed to interfere with the power of the State, sometimes termed its police power, to prescribe regulations to promote the health, peace,, morals, education and good order of the people, and to legislate so as to increase the industries of the State, develop its resources, and add to its wealth and prosperity.”

Further, as the rule of construction, Chief Justice Marshall, speaking for the court in the great case of McCulloch v. Maryland, 4 Wheat. 316, 405, declares:

“This Government is acknowledged by all to be one of enumerated powers. The principle that it can exercise only the powers granted to it would seem too apparent, to have required to be enforced by all those arguments which its enlightened friends, while it was depending before the people; found it .necessary to urge. That .principle is now universally admitted. But the question respecting the extent of the powers actually granted is perpetually arising, and will probably continue to arise, as long as our system shall .exist.”

In Houston v. Moore, 5 Wheat. 1, 48, Mr. Justice Story says.-

“Nor ought any power to be sought, much less to he adjudged, in favor of the United States, unless it be clearly within the reach of its constitutional charter. Sitting here, we are not at liberty to add one jot of power to the National Government beyond what the people have granted by the Constitution.”. Art. X of Amendments; City of New York v. Miln, 11 Pet. 102, 133; License Cases, 5 How. 504, 608, 630; United States v. Dewitt, 9 Wall. 41, 44; Patterson v. Kentucky, 97 U. S. 501, 503; Barbier v. Connolly, 113 U. S. 27, 31; In re Rahrer, 140 U. S. 545, 555; United States v. Knight, 156 U. S. 1, 11; Cooley’s Constitutional Limitations, 574..

Doubtless it not infrequently happens that the same act *146may be referable to the power of the State, as well as to that Of Congress. If there be collision in such a case, the superior authority of Congress prevails. As said in City of New York v. Miln, 11 Pet. 102, 137:

“From this it appears that whilst a State is acting within the legitimate scope of its power as to the end to be attained, it may use whatsoever 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. The court must be understood, of course, as meaning that the law of Congress is passed upon a subject within the sphere of its power.”

In Gulf, Colorado & Santa Fe Railway v. Heftey, 158 U. S. 98, 104, the rule.is stated in these words:

“Generally it may be said in respect to laws of this character that, though resting upon the police power of the State, they must yield whenever Congress, in the exercise of the powers granted to it, .legislates upon the precise subject-matter, for that power, like all other reserved powers of the States, is subordinate to those in terms conferred by the Constitution upon the nation. ‘No urgency for its use can authorize a State to exercise it in regard to a subject-matter which has been, confided exclusively to the discretion of Congress by the Constitution. Henderson v. New York, 92 U. S. 259, 271. ‘Definitions of the police power must, however, be taken subject to. the condition that the State cannot, in its exercise, for any purpose whatever, encroach upon the powers of the General Government, or rights granted or secured by the supreme law of the land.’ New Orleans Gas Co. v. Louisiana Light Co., 115 U. S. 650, 661. ‘While it may be a police power in the sense that all provisions for the health, comfort, and security of the citizens are police regulations, and an exercise of the police power, it has been said more than once in this court that, where such powers are so exercised as to com.e within the domain of Federal authority as defined *147by the Constitution, the latter must prevail.' ” Morgan v. Louisiana, 118 U. S. 455, 464. See also Lottery Case, 188 U. S. 321.

The question is, therefore, whether there is any authority conferred upon Congress by which this particular portion of the statute can be sustained. By § 2 of Art. II of the Constitution, power is given to the President, by and with the' advice and consent of the Senate, to make treaties, but there is no suggestion in the record or in the briefs of a treaty with the King of Hungary under which this legislation can be supported.

The general power which exists in the Nation to control the coming in or removal of aliens is relied upon, the Government stating in its brief these two propositions:

“The clause in question should be held valid because it relates to and materially affects the conditions upon which an alien female may be permitted to remain in this country, and the grounds which warrant her exclusion.

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“The validity of the provision in question should be determined from its general effect upon the importation and exclusion of aliens.”

But it is sufficient to say that the act charged has no significance in either direction. .

As to the suggestion that Congress has power to punish one assisting in the importation of a prostitute, it is enough to say that the statute does not include such a charge; the indictment does not make it, and the testimony shows, without any contradiction, that the woman, Irene Bodi, came to this country in November, 1905; that she remained in New York until October, 1907; then came to Chicago and went into the house of prostitution which the defendants purchased in November, 1907, finding the woman then in the house; that she had been in the business of a prostitute- only about ten or eleven months prior to the trial of the case in October, 1908, and that the defendants did not know her until November, 1907. In view of those facts the question of the. power of Congress to punish *148those who assist in the importation of a prostitute is entirely immaterial.

The act charged is only one included in the great mass of personal dealings with aliens. It is her own character and conduct which determines the question of exclusion or removal. The acts of others may be evidence of her business and character. But it does not follow that Congiess has the power td’ punish those whose acts furnish evidence, from which the Government may determine the question of her expulsión. Every possible dealing oh any citizen with the alien may have more or less induced her coming. E^ut can it be within the power of Congress to control all the dealings of our citizens with resident aliens? If that be possible, the door is open to the assumption by the National Government of an almost unlimited body of legislation. By the census of 1900 the population of the United States between the oceans was in round numbers 76,000,000. Of these, 10,000,000 were of foreign birth,,„and 16,000,000 more 'were of foreign parentage. Doubtless some have become citizens by naturalization, but certainly scattered through the country there are millions of aliens.. .If the contention of the Government be sound, whatever may have been done in the past, however little this 'field of legislation may have been entered upon, the power of Congress is broad enough to take cognizance of all dealings of citizens with aliens. That there is a moral consideration in the special facts of this case, .that the act charged is within the scope of the police power, is immaterial, for, as stated, there is in the Constitution no grant to Congress of the. police power. And the legislation must stand or fall according to the determination of the'question of 'the’power of Congress to control generally dealings of citizen?‘with aliens. In other words, an immense body of legislation; which heretofore has been recognized as peculiarly withinMhe jurisdiction of the States, may be taken by Congress away- from them. Although Congress has not largely entered, into this field of legislation, it may do so, if it’has the power, Then we should be brought face to face with such a change in the internal conditions of this country *149as was never dreamed of by the framers of the ’Constitution. While the acts of Congress are to be liberally construed in order to enable it to carry into-effect the powers conferred, it is equally true that prohibitions and limitations upon those powers should also be fairly and reasonably enforced. Fairbank v. United States, 181 U. S. 283. To exaggerate in the one direction and restrict in the other will tend to substitute one consolidated government for the present Federal system. We should never •forget the declaration in Texas v. White, 7 Wall. 700, 725, that “the Constitution, in all its provisions, looks to an indestructible Union, composed of indestructible States.”

The judgments are reversed, and the cases remanded to the District Court of the United States for the Northern District of Illinois with instructions to quash the indictment.

dissenting.

For the purpose of excluding those who unlawfully enter this country Congress has power' to retain control oyer aliens long enough to make sure of the facts. Yamataya v. Fisher (Japanese Immigrant Case), 189 U. S. 86. To this end it may make their admission conditional for three years. Pearson v. Williams, 202 U. S. 281. If the ground of exclusion is their calling, practice of it within a short time after arrival is or may be made evidence of what it was when they came in. Such retrospective presumptions are not always contrary to experience or unknown to the law. Bailey v. Alabama, 211 U. S. 452, 454. If a woman were found living in a house of prostitution within a week of her arrival, no one, I suppose, would doubt that it tended to show that she was in the business when she arrived. But how far. back such an inference shall reach is a question of degree like most of the questions of life. And, while a period of three.years seems to be long, I am not prepared to say, against the judgment of Congress, that it is too long.

The statute does not state the legal theory upon which it was enacted.. If the ground is that which I have suggested, it is fair *150to observe that the presumption that it creates is not open to rebuttal. I should be prepared to accept even that, however, in view of the difficulty of proof in such cases. Statutes of which the justification must be the same ar§ familiar in the States. For instance, one creating the offense'of being present when gaming implements are found, Commonwealth v. Smith, 166 Massachusetts, 370, 375, 376, or punishing the sale of intoxicating liquors without regard to knowledge of their intoxicating quality, Commonwealth v. Hallett, 103 Massachusetts, 452, or throwing upon a seducer the risk of the woman turning out to be married or under a certain age. Commonwealth v. Elwell, 2 Met. 190; Reg. v. Prince, L. R. 2 C. C. 154. It is true that in such instances the legislature has power to change the substantive law of crimes, and it has been thought that when it is said to create a conclusive presumption as to a really disputable fact, the proper mode of stating what it does, at least as a general rule, is to say that it has changed the substantive law. 2AWigmore, Ev., §§ 1353 ef seq. This may be admitted without denying that considerations of evidence .are what lead to the change. And if it should be thought more philosophical to express this law in substantive terms, I think that Congress may require, as a condition of the right to remain, good behavior for a certain time, in matters deemed by it important to the public welfare and of a kind that indicates a preexisting habit that would have excluded the party if it had been known. Therefore I am of opinion that it is within the power of Congress to order the deportation of a woman found practicing prostitution within three years.

If Congress can forbid the entry and order the subsequent deportation of professional prostitutes, it can punish those who cooperate in their fraudulent entry. “If Congress has power to exclude such* laborers ... it has the power to punish any who assist in their introduction.” That was a point decided in Lees v. United States, 150 U. S. 476, 4807 The same power must exist as to cooperation in an equally unlawful stay. The indictment sets forth the facts that constitute such cooperation *151and need not allege the conclusion of law. On the principle of the cases last cited, in order to make its prohibition effective the law can throw the burden of finding out the fact and date of a prostitute’s arrival from another country upon those who harbor her for a purpose that presumably they know in any event to be contrary to law.' Therefore, while I have admitted that the time fixed seems to me to be long, I can see no other constitutional objection to the act, and, as I have said, I think that that one ought not to prevail-