delivered the opinion of the court.

The gravamen of the bill was the injury to the health, morals, peace and good order of the people of th¿ town and county, the .infliction of which ivas alleged to be threatened by the[*188] bringing within their precincts of certain persons by defendants. No statute of the State was referred to as applicable, but the enforcement of the police power was sought through the interposition of a court of equity by way of prevention of an impending public nuisance. The Circuit Court was of opinion that the bill could not be maintained, but, without intimating any conclusion to the contrary, or.criticising its formal sufficiency, the question that meets us on the threshold is whether the case ought to have been remanded to the state court.

We need not spend any' time on the contention that this was a controversy between citizens of different States. The Circuit Court correctly held otherwise. The State of Arkansas was the party complainant, and a State is not a citizen. Postal Telegraph Cable Company v. Alabama, 155 U. S. 482.

We inquire, then, if the cause was removable because arising under the Constitution or laws of the United States.

The general policy of the act of March 3, 1887, as correóted by the act of August 13, 1888, (24 Stat. 552, c. 373; 25 Stat. 433, c. 866,) as is apparent on its face, and as has been repeatedly recognized by'this court, was to contract the jurisdiction of the Circuit Courts. Those cases, and those only, were made removable under section two, in respect of which original'jurisdiction was given to the Circuit Courts by. section one. Hence it has been settled that a case cannot be removed from a state court into the Circuit Court of the United States on the sole ground that it is one arising under the Constitution, laws of treaties of the United States, unless that appears by plaintiff’s statement of his own claim; and if it does not so appear, the want of it cannot be supplied by any statement of the petition for removal or in the subsequent pleadings. And moreover that jurisdiction is not conferred by allegations that defendant intends to assert a defence based on the Constitution or a law or treaty of the United States, or under statutes of the United States, or of a-State, in conflict with the Constitution. Tennessee v. Union & Planters' Bank, 152 U. S. 454; Chappell v. Waterworth, 155 U. S. 102; Walker v. Collins, 167 U. S. 57; Sawyer v. Kockersperger, 170 U. S. 303; Florida Central & Peninsula Railroad v. Bell, 176 U. S. 321.

[*189] In this case the State asserted no right under the Constitution or laws of the United States, and put forward ho ground of relief derived from either. There • were no averments on which the State could have .invoked the original jurisdiction of the Circuit Court under section one of. the act, and that is the test of the. right of removal under section two.

The police power was appealed to, the power to protect life, liberty and property, to conserve the public health and good order, which always belonged, to the States, and was not surrendered to the general government, or directly restrained by the Constitution. The Fourteenth Amendment, in forbidding a State to make or enforce any law abridging the privileges or immunities of citizens of the United States, or to deprive any person of' life, liberty or property without due process of law, or to deny to any person within its jurisdiction the equal pro-' .tection of the laws, did not invest Congress with power to legislate upon subjects which are within the domain of state legis-' lation. In re Rahrer, 140 U. S. 545, 554. It is true that when the police power and the commercial power come into collision, that which is not supreme must give way to that which is supreme. But how is such collision made to appear %

' Defendants argue that the Circuit Court might have properly • taken judicial' notice, or did so, of the fact, that the persons whose,advent was objected to as perilous to the community could only be brought to Huntington by way of the Indian Territory, and also that the word “ import ” as used in the bill meant to bring into from another State or foreign country; that, therefore, “ the question .is fairly presented by the complaint whether the State of Arkansas has the authority to prevent the coal company and, the railroad company from bringing, into the State over, the line of this railroad,' laborers from other States or foreign, countries and hence that the Circuit Court had jurisdiction. .We do not agree with either-premise or conclusion.

Th,e word “import” necessarily meant bringing into the county and' town from outsidé their boundaries, but we do not think, taking the whole bill together, that as here used its nec-_, essary signification was the bringing in from outside of the State. •

[*190] And as to judicial knowledge, tbe principle applies “ that the right of a court to act upon what is in point of fact known to it must be subordinate to those requirements of form and orderly communication which regulate the mode of bringing .controversies into court, and of stating and conducting them.” Thayer, Ev. ch. YII, 281.

In Mountain View Mining & Milling Co. v. McFadden, 180 U. S. 533, which was a petition for removal, the suit was one brought in support of an adverse claim under the Revised Statutes, sections 2325, 2326, and it had been previously, decided that such a suit was not one arising under the laws of the United States in such a sense as to confer jurisdiction on the Federal courts regardless of the citizenship of the parties. And we said: ‘It is conceded by counsel on both sides that those decisions, are controlling, unless the Circuit. Court was entitled to maintain jurisdiction by taking judicial notice of the fact ‘that the-Mountain Yiew lode claim was located upon what had been or was an Indian reservation,’ and ‘ of the act of Congress declaring the north half of the reservation, upon which the claim was located, to have been restored' to the public ' domain; ’ notwithstanding no claim based on these facts was. stated in the complaint. Rut the Circuit Court could, not make plaintiffs’ case other than they made it by taking judicial notice of facts which they did not choose to rely on in their pleading. The averments brought no controversy in this regard into court, in respect of which resort might be had to judicial knowledge.” Oregon Short Line &c. Railway v. Skottowe, 162 U. S. 490; Chappell v. Waterworth, 155 U. S. 102; Commonwealth v. Wheeler, 162 Mass. 429; P artridge v. Strange, Plowden, 77.

But even assuming that the bill showed upon its face that the .relief sought would be inconsistent with the power to regulate commerce, or with regulations established by Congress, or with the Fourteenth Amendment, as contended, it would only demonstrate that the bill could not be maintained at all, and not that the cause of action arose under the Constitution or laws of the United States.

When Federal questions arise in cases pending in the state courts, those, courts are competent, and it is their duty, to decide[*191] them. If errors supervene, the remedy by writ of error is open to the, party aggrieved. Robb v. Connolly, 111 U. S. 624, 637.

Decree reversed and canse remanded with a direction to remand to the state court. Costs of this court and of the Circuit Court to be paid by the appellees and defendants.