delivered the opinion of the Court.

Appellants brought this spit to enjoin the Attorney General of Washington from enforcing the Anti-Alien Land Law of that State, c. 50, Laws, 1921, on the grounds that it is in conflict with the due process and.equal protection clauses of the Fourteenth Amendment; with'the treaty between the United States and Japan, and with certain provisions of the constitution of the State.

The" appellants are residents of Washington. ' The Terraces are citizens of the United States and of Washington. Nakatsuka was born in Japan of Japanese parents and is a subject of the Emperor of Japan. The Terraces are the owners of a tract of land in King County which is particularly adapted to raising vegetables^ and which for a number of years had been devoted to that and other agricultural purposes. The complaint alleges that Nakatsuka' is a capable farmer and will be a désirable tenant of the land; that the Terraces desire to lease their land to him for the period of five years; that he desires to accept such lease, and that the lease would be made but *212 for the act complained of. And it' is alleged that the defendant, as Attorney ‘General, has threatened to and will take steps to enforce the act against the appellants if they enter into such lease, and will, treat the leasehold interest as forfeited to the State, and will prosecute the appellants criminally for violation of the act; that the act is so drastic and the penalties attached to its violation are so great that neither of the appellants may make the lease even to test the constitutionality of the act, and that, unless the court shall determine its validity in this suit, the appellants will be compelled to submit to it,- whether valid or invalid, and thereby will be deprived of their ■property without due process of law and denied the equal protection of the laws.

The Attorney General made a motion to dismiss the amended complaint upon the ground that it did not state any matters of equity or facts sufficient to entitle the appellants • to relief. The District Court granted the motion and entered a decree of dismissal on the merits. The case is here on appeal from that decree.

Section 33 1 of Article-II of the Constitution of Washington prohibits the ownership of land by aliens other' •than those who in good faith have declared intention to becbme citizens oí the United States, except in certain *213 instances not here involved. The act 2 provides in substance that any such alien shall not own, take, have or hold the legal or equitable title, or right to any benefit of any land as defined in the act, and that land conveyed to or for the use of aliens in violation of the state constitution or of the act shall thereby be forfeited to the State. And it is made a gross misdemeanor, punishable by fine or imprisonment or both, knowingly to transfer land or the right to the control, possession or use of land to such an alien. It is also made a gross misdemeanor for any such alien having title to such land or the control,-possession or use thereof, to refuse to disclose to the Attorney General or the prosecuting attorney the nature and extent of his interest in the land. The Attorney General and the prosecuting attorneys of the several counties are charged with the enforcement of the act.

*214 1. The Attorney General questions the jurisdiction of the court to grant equitable relief even if the statute be unconstitutional. He contends that the appellants have a plain, adequate and speedy remedy at law; that the case involves but a single transaction, and that, if the proposed lease is made, the only remedy which the State has, so far as civil proceedings are concerned, is an escheat proceeding in which the validity of the law complained of may be finally determined; that an acquittal of the-■Terraces of the criminal offense created by the statute would protect them from further prosecution, and that Nakatsuka is liable criminally only upon his failure to disclose the fact that he holds an interest in the land.

The unconstitutionality of a state law'is not of itself .ground for equitable, relief in the courts of the United States. That a suit in equity does not-lie where there is a plain, adequate and complete remedy at law is so well understood as not to require the citation of authorities. But the legal remedy must be as complete, practical and efficient as that which equity could afford. Boise Artesian Water Co. v. Boise City, 213 U. S. 276, 281; Walla Walla City v. Walla Walla Water Co., 172 U. S. 1, 11, 12. Equity jurisdiction will be exercised to enjoin the threatened enforcement of a state law which contravenes tKe Federal Constitution wherever it is essential in order effectually' tó protect property rights and the rights of-persons against injuries otherwise irremediable; and in such a case a person, who as an officer of the State is clothed with the duty of enforcing its laws and who -threatens andis ábout to commence proceedings, either civil or criminal, to'-enforce such a law against parties affected, may be enjoined from such action by a federal court of equity. Cavanaugh v. Looney, 248 U. S. 453, 456; Truax v. Raich, 239 U. S. 33, 37, 38. See also Ex parte Young, 209 U. S. 123, 155, 162; Adams v. Tanner, 244 U. S. 590, 592; Greene v. Louisville & Interurban *215 R. R. Co., id. 499, 506; Home Telephone & Telegraph Co. v. Los Angeles, 227 U. S. 278, 293; Philadelphia Co. v. Stimson, 223 U. S. 605, 621; Western Union Telegraph Co. v. Andrews, 216 U. S. 165; Dobbins v. Los Angeles, 195 U. S. 223, 241; Davis & Farnum Manufacturing Co. v. Los Angeles, 189 U. S. 207, 217.

The Terraces’ property rights in the land include the right to use, lease arid dispose of it for lawful purposes (Buchanan v. Warley, 245 U. S. 60, 74), and the Constitution protects these essential attributes of property (Holden v. Hardy, 169 U. S. 366, 391), and also protects Nakatsuka in his right to earn a livelihood by following the ordinary occupations of life. Truax v. Raich, supra; Meyer v. Nebraska, 262 U. S. 390. If, as claimed, the state act is repugnant to the due process and equal protection clauses of the Fourteenth Amendment, then its enforcement will deprive, the owners of. their right to-lease their land to Nakatsuka, and deprive him of his right to pursue the occupation of farmer, and the threat to enforce it constitutes a continuing unlawful restriction upon and infringement of the rights of appellants, as to which they have no remedy at law which is,as practical, efficient or adequate as the remedy in equity. And assuming, as suggested by the Attorney General, that after the making of the lease the validity of the law might be determined in proceedings to declare- a forfeiture of the property to the State or in criminal proceedings to punish ■the owners, it does not follow that they may not appeal to equity for i-*ief. No action at law can be initiated against them until after the consummation of the proposed lease. The threatened enforcement of the law deters them. In order to 'obtain a remedy at law, the owners, even if they would take the risk of fine, imprisonment and'loss of property, must continue to suffer deprivation of their right to dispose of or lease their land to any such alien until one is found who will join them *216 in violating the terms of the enactment and take the risk of forfeiture. Similarly Nakatsuka must continue to.be deprived of his right to follow his occupation as farmer until a land owner is found who is willing to make a forbidden transfer of land and take the risk of punishment. The owners have an interest in the freedom of the alien, and he has an interest in their freedom, to make the lease. The state act purports to operate directly upon the consummation of the proposed transaction between them, and the threat and purpose of the Attorney General to enforce the punishments and forfeiture prescribed prevent each from dealing with the other. Truax v. Raich, supra. They are not obligéd to take the risk of prosecution, finés and imprisonment and loss of property in order to secure an adjudication of their rights. , The complaint, presents a case in which equitable relief may be had, if the law complained of is shown to be in contravention of the Federal Constitution.

2. Is the act repugnant to the due process clause or the equal protection clause of the Fourteenth Amendment?

Appellants contend that the act contravenes the due process clause in that it prohibits the owners from making lawful disposition or use of their land, and makes it a criminal offense for them to lease it to the alien, and prohibits him from following the occupation of farmer; and they contend that it is repugnant to the equal protection clause in that aliens are divided into two classes, — those who may and those who may not become citizens, one class being permitted, while the other is forbidden, to own land as defined.

Alien inhabitants of a State, as well as all other persons within its jurisdiction, may invoke the protection of these clauses. Yick Wo v. Hopkins, 118 U. S. 356, 369; Truax v. Raich, supra, 39. The Fourteenth Amendment, as against the arbitrary and capricious or unjustly discriminatory action of the State, protects the owners in their *217 right to lease and dispose of their land for lawful purposes and the alien resident in his right to earn a living by following ordinary occupations of the community, but it does not take away from the State those powers of police that were reserved at the time of the adoption of. the Constitution. Barbier v. Connolly, 113 U. S. 27, 31; Mugler v. Kansas, 123 U. S. 623, 663; Powell v. Pennsylvania, 127 U. S. 678, 683; In re Kemmler, 136 U. S. 436, 449; Lawton v. Steel, 152 U. S. 133, 136; Phillips v. Mobile, 208 U. S. 472, 479; Hendrick v. Maryland, 235 U. S. 610, 622, 623. And in the exercise of such powers the State has wide discretion in determining its own public policy and what measures are necessary for its own protection and properly to promote the safety, peace and good order of its people.

And, while Congress has exclusive jurisdiction over immigration, naturalization and the disposal of the public domain, each State, in the absence of any treaty provision to the contrary, has power to deny to aliens the right to own land within its borders. Hauenstein v. Lynham, 100 U. S. 483, 484, 488; Blythe v. Hinckley, 180 U. S. 333, 340. Mr. Justice Field, speaking for this Court (Phillips v. Moore, 100 U. S. 208) said (p. 212):

“ By the common law, an alien cannot acquire real property by operation of law, but may take it by act of the grantor, and hold it until office found; that is, until the fact of alienage is authoritatively established by a public officer, upon an inquest held at the instance of the government.” 3

*218 State' legislation applying alike and equally to i '.1 aliens, withholding from them the right to own land, cannot be said to be capricious or to amount to an arbitrary deprivation of liberty or property, or to transgress the due process clause.

This brings us to a consideration of appellants’ contention that the act contravenes the equal protection clause. That clause secures equal protection to all in the enjoyment of their rights under like circumstances. In re Kemmler, supra; Giozza v. Tiernan, 148 U. S. 657, 662. But this does not forbid every distinction in the law of a State between citizens and aliens resident therein. In Truax v. Corrigan, 257 U. S. 312, this Court said (p. 337):

“ In adjusting legislation to the need of the people of a State, the legislature has a wide discretion and it may be fully conceded that perfect uniformity of treatment of all persons is neither practical nor desirable, that classification of persons is constantly necessary. . . Classification is the most inveterate of our reasoning processes. We can scarcely think or speak without consciously or unconsciously exercising it. It must therefore obtain in and determine legislation; but it must regard real resemblances and real differences between things, and persons, and class them in accordance with their pertinence to the purpose in hand.”

The rights, privilege's and duties of aliens differ widely from those of citizens; and those of alien declarants differ substantially from those of nondeclarants. Formerly in many of the States the right to vote and hold office was extended to declarants, and many important offices have been held by them. But these rights have not been granted to nondeclarants. By various acts of Congress, 4 *219 declarants have been made liable to military duty, but no act has imposed that' duty on nondeclarants. The fourth paragraph of Article I of the treaty invoked by the appellants, provides that the citizens or subjects of each shall be exempt in the territories of the other from compulsory military service either on land or sea, in the regular forces, or in the national guard, or in the militia; also from all contributions ijnposed in lieu of personal service, and from all forced loans or military exactions or contributions. The alien’s formally declared bona fide intention to renounce forever all allegiance and fidelity to the sovereignty to which he lately has been a subject, and to become a citizen of the United States and permanently to reside therein 5 markedly distinguishes him from an ineligible alien or an eligible alien who has not so declared.

By the statute in question all aliens who have not in good faith declared intention to become citizens of the United States, as specified in § 1 (a), are called “aliens,” and it is provided that they shall not “ own ” “ land,” as defined in plauses (d) and (b) of § 1 respectively. The class so created includes all, but is not limited to, aliens not eligible to become citizens. Eligible aliens who have not declared their intention to become citizens are included, and the act provides that unless declarants be admitted to citizenship within seven years after the declaration is made, bad faith will be presumed. This leaves the class permitted so to own land made up of citizens and aliens who may, and who intend to, become citizens, and who in good faith have made the declaration required by the naturalization laws. The inclusion of good faith declarants in the same class with citizens does not unjustly discriminate against aliens who are ineligible or *220 against eligible alien» who have failed to -declare their intention. The classification is based on eligibility and purpose to naturalize. Eligible aliens are free white persons and persons of African nativity or descent. 6 Congress is not trammeled, and it may grant or withhold the privilege of naturalization upon any grounds' or without any reason, as it sees fit. But it is not to be supposed that its acts defining eligibility are arbitrary or unsupported by reasonable considerations of public policy. The State properly may assume that the considerations upon which Congress made such - classification are. substantial and reasonable. -Generally speaking, the natives of .European countries are eligible. Japanese, Chinese and Malays are not. Appellants’ contention that the state act discriminates arbitrarily against Nakatsuka and other ineligible aliens because of their race and color is without foundation. All persons of whatever color or race who have not declared their intention in good faith to become citizens are prohibited from so owning agricultural lands. • Two classes of aliens inevitably result from the naturalization laws, — -those who may and those who may not become citizens. The rule established by Congress on this subject, in and of itself, furnishes a reasonable • basis for classification in a state law withholding from aliens the privilege of land ownership as defined in the act. We agree with the court'below (274 Fed. 841, 849) that:

■. “ It is obvious that one who is not a citizen and cannot become one lacks an interest in, and- the power to effectually work for the welfare of, the state, and, so lacking, the state may rightfully deny him the right to own and lease real estate within its boundaries. If one incapable of citizenship may lease or own real estate, it is within the *221 realm of possibility that every foot of land within the state might pass to the ownership or possession of non-citizens.”

And we think it is clearly within the power of the State to include nondeclarant eligible aliens and ineligible aliens in the same prohibited class. Reasons supporting discrimination against aliens who may but who will not naturalize are obvious.

Truax v. Raich, supra, does not support the appellants’ contention. In that case, the Court held to be repugnant to the Fourteenth Amendment an act of the legislature of Arizona making it a criminal offense for an employer of more than five workers at any one time, regardless of kind or class of work, or sex of workers, to employ less than eighty per cent, qualified, electors or native born citizens of the United States. In the opinion it was pointed out that the legislation there in question did not relate to the devolution of real property, but that the discrimination was imposed upon the conduct of ordinary private enterprise covering the entire field of industry-with the exception of enterprises that were relatively very small. It was said that the right to work for a living in the common occupations of the community is a part of the freedom which it was the purpose of the Fourteenth Amendment to secure.

In the case before us, the thing forbidden is very different. It is not an opportunity to earn a living in common occupations of the community, but it is the privilege of owning or controlling' agricultural land within the State. The quality and allegiance of those who own, occupy and use the farm lands within its borders are matters of highest importance and affect the safety and power of the State itself.

The Terraces, who are citizens, have no right safeguarded by the Fourteenth Amendment to lease their land to aliens lawfully forbidden to take or have such lease. *222 The state act is not repugnant .to the equal' protection clause and does not contravene the Fourteenth Amenu • ment.

3. The state act, in our opinion, is not in conflict with the treaty 7 between the United States and Japan. The preamble declares it to be “ a treaty of commerce and navigation ”, and indicates that it was entered into for the purpose of establishing the rules to govern commercial intercourse between the countries.

The only provision that relates to owning or leasing land' is in the first paragraph of Article I, which is as follows:

“ The citizens or subjects of each of the High Contracting Parties shall have, liberty to enter, travel and reside in' the territories of the other to carry on trade, wholesale and retail, .to.own or lease and occupy houses, manufac-tories, warehouses and' shops, to employ agents of their choice,- to lease land for residential and commercial purposes, and generally to do anything incident to or necessary for trade upon the same terms as native citizens or subjects, submitting themselves to the laws and regulations'there established.”

For the purpose of bringing Nakatsuka within the protection of the treaty, the amended complaint alleges that, in addition to being a capable farmer, he is engaged in the business of trading, wholesale and'retail, in farm products and shipping the same in intrastate, interstate and foreign commerce; and, instead of purchasing such farm-products, he has produced, and desires to continue to produce, his own farm products for the. purpose of selling them in such wholesale and retail trade, and if he is prevented from leasing land for the purpose of producing farm products for such trade he will be prevented from ■ engaging in,-trade and the incidents to trade, as he is authorized td-do under the treaty.

*223 To prevail oil this point, appellants must show conflict between the state act and the treaty. Each State, in the absence of any treaty provision conferring the right, may enact laws prohibiting aliens from owning land within its borders. Unless the right to own or lease land is given by the treaty, no question of conflict can arise. We think that the treaty not only contains no provision giving Japanese the right to own or lease land for agricultural purposes, but, when viewed in the light of the negotiations leading up to its consummation, the language shows that the high contracting parties respectively intended to withhold a treaty grant of that right to the citizens or subjects of either in the territories of the other. .The right .to “ carry on trade ” or “ to own or lease and occupy houses, manufactories, warehouses and shops ”, or “ to lease'land for residential and commercial purposes ”, or “ to do anything incident to or necessary for trade ” cannot be said to include the right to own or lease or to have any title to or interest in land for agricultural purposes. The enumeration of rights to own or lease for other specified .purposes impliedly negatives the right to own or lease land for these purposes. A careful reading of the treaty suffices in our opinion to negative the claim asserted by appellants that it conflicts with the state act.

But if the language left the meaning of its provisions doubtful or obscure, the circumstances of the making of the treaty, as set forth in the opinion of the District Court (supra, 844, .845), would resolve all doubts against the appellants’ contention. The letter of Secretary of State Bryan to Viscount Chinda, July 16, 1913, shows-that, in accordance with the desire of Japan, the right to own land was not conferred. And it appears that the right to lease land for other than residential and commercial purposes was deliberately withheld by substituting the words of the treaty, “ to lease land for residential and commercial purposes” for a more comprehensive clause *224 contained in an earlier draft of the instrument, namely, “ to lease land for residential, commercial, industrial, manufacturing and other lawful purposes.”

4. The act complained of is not repugnant to § 33 of Article II of the state constitution.

That section provides that “ the ownership of lands by aliens ... is prohibited in .this State . . .”. Appellants assert that the proposed lease of farm land for five .years is not “ ownership ”, and is not prohibited by that clause of the state constitution and cannot be forbidden by the state legislature. That position is untenable. In State v. O’Connell, 121 Wash. 542, a suit for the purpose of escheating to' the State an undivided one-half interest in land, or the proceeds thereof, held in trust for the benefit of an alien, a subject of the British Empire, decided since this appeal was taken, the Supreme Court of Washington held that the statute in question did not contravene this provision of the constitution of that State. The question whether or not a state statute conflicts with the constitution of the State is settled by the decision of its highest court. Carstairs v. Cochran, 193 U. S. 10, 16. This Court “ is without authority to review and revise the construction affixed .to a' state statute as to a state matter by the court of last resort of the State ”. Quong Ham Wah Co. v. Industrial Commission, 255 U. S. 445, 448, and cases cited.

The decree of the District Court is affirmed.