Opinion of the Court. 356 U.S. Statutory expatriation, as a response to problems of international relations, was first introduced just a half century ago. Long before that, however, serious friction between the United States and other nations had stirred consideration of modes of dealing with the difficulties that arose out of the conflicting claims to the allegiance of foreign-born persons naturalized in the United States, particularly when they returned to the country of their origin. As a starting point for grappling with this tangle of problems, Congress in 1868 formally announced the traditional policy of this country that it is the "natural and inherent right of all people" to divest themselves of their allegiance to any state, 15 Stat. 223, R. S. § 1999. Although the impulse for this legislation had been the refusal by other nations, notably Great Britain, to recognize a right in naturalized Americans who had been their subjects to shed that former allegiance, the Act of 1868 was held by the Attorney General to apply to divestment by native-born and naturalized Americans of their United States citizenship. 14 Op. Atty. Gen. 295, 296. In addition, while the debate on the Act of 1868 was proceeding, negotiations were completed on the first of a series of treaties for the adjustment of some of the disagreements that were constantly arising between the United States and other nations concerning citizenship. These instruments typically provided that each of the signatory nations would regard as a citizen of the other such of its own citizens as became naturalized by the other. E. g., Treaty with the North German Confederation, Feb. 22, 1868, 2 Treaties, Conventions, International Acts, etc. (comp. Malloy, 1910), 1298. This series of treaties initiated this country's policy of automatic divestment of citizenship for specified conduct affecting our foreign relations. 44 Opinion of the Court. On the basis, presumably, of the Act of 1868 and such treaties as were in force, it was the practice of the Department of State during the last third of the nineteenth century to make rulings as to forfeiture of United States citizenship by individuals who performed various acts abroad. See Borchard, Diplomatic Protection of Citizens Abroad, §§ 319, 324. Naturalized citizens who returned to the country of their origin were held to have abandoned their citizenship by such actions as accepting public office there or assuming political duties. See Davis to Weile, Apr. 18, 1870, 3 Moore, Digest of International Law, 737; Davis to Taft, Jan. 18, 1883, 3 id., at 739. Native-born citizens of the United States (as well as naturalized citizens outside of the country of their origin) were generally deemed to have lost their American citizenship only if they acquired foreign citizenship. See Bayard to Suzzara-Verdi, Jan. 27, 1887, 3 id., at 714; see also Comitis v. Parkerson, 56 F. 556, 559. No one seems to have questioned the necessity of having the State Department, in its conduct of the foreign relations of the Nation, pass on the validity of claims to American citizenship and to such of its incidents as the right to diplomatic protection. However, it was recognized in the Executive Branch that the Department had no specific legislative authority for nullifying citizenship, and several of the Presidents urged Congress to define the acts by which citizens should be held to have expatriated themselves. E. g., Message of President Grant to Congress, Dec. 7, 1874, 7 Messages and Papers of the Presidents (Richardson ed. 1899) 284, 291-292. Finally in 1906, during the consideration of the bill that became the Naturalization Act of 1906, a Senate resolution and a recommendation of the House Committee on Foreign Affairs called for an examination of the problems relating to American citizenship, expatriation and protection Opinion of the Court. 356 U.S. abroad. In response to these suggestions the Secretary of State appointed the Citizenship Board of 1906, composed of the Solicitor of the State Department, the Minister to the Netherlands and the Chief of the Passport Bureau. The board conducted a study and late in 1906 made an extensive report with recommendations for legislation. Among the recommendations of the board were that expatriation of a citizen "be assumed" when, in time of peace, he became naturalized in a foreign state, engaged in the service of a foreign state where such service involved the taking of an oath of allegiance to that state, or domiciled in a foreign state for five years with no intention to return. Citizenship of the United States, Expatriation, and Protection Abroad, H. R. Doc. No. 326, 59th Cong., 2d Sess. 23. It also recommended that an American woman who married a foreigner be regarded as losing her American citizenship during coverture. Id., at 29. As to the first two recommended acts of expatriation, the report stated that "no man should be permitted deliberately to place himself in a position where his services may be claimed by more than one government and his allegiance be due to more than one." Id., at 23. As to the third, the board stated that more and more Americans were going abroad to live "and the question of their protection causes increasing embarrassment to this Government in its relations with foreign powers." Id., at 25. Within a month of the submission of this report a bill was introduced in the House by Representative Perkins of New York based on the board's recommendations. Perkins' bill provided that a citizen would be "deemed to have expatriated himself" when, in peacetime, he became naturalized in a foreign country or took an oath of allegiance to a foreign state; it was presumed that a naturalized citizen who resided for five years in a foreign state had 44 Opinion of the Court. ceased to be an American citizen, and an American woman who married a foreigner would take the nationality of her husband. 41 Cong. Rec. 1463-1464. Perkins stated that the bill was designed to discourage people from evading responsibilities both to other countries and to the United States and "to save our Government [from] becoming involved in any trouble or question with foreign countries where there is no just reason." Id., at 1464. What little debate there was on the bill centered around the foreign domicile provision; no constitutional issue was canvassed. The bill passed the House, and, after substantially no debate and the adoption of a committee amendment adding a presumption of termination of citizenship for a naturalized citizen who resided for two years in the country of his origin, 41 Cong. Rec. 4116, the Senate passed it and it became the Expatriation Act of 1907. 34 Stat. 1228. The question of the power of Congress to enact legislation depriving individuals of their American citizenship was first raised in the courts by Mackenzie v. Hare, 239 U. S. 299. The plaintiff in that action, Mrs. Mackenzie, was a native-born citizen and resident of the United States. In 1909 she married a subject of Great Britain and continued to reside with him in the United States. When, in 1913, she applied to the defendants, members of a board of elections in California, to be registered as a voter, her application was refused on the ground that by reason of her marriage she had ceased to be a citizen of the United States. Her petition for a writ of mandamus was denied in the state courts of California, and she sued out a writ of error here, claiming that if the Act of 1907 was intended to apply to her it was beyond the power of Congress. The Court, through Mr. Justice McKenna, after finding that merging the identity of husband and wife, as Congress had done in this instance, had Opinion of the Court. 356 U.S. abroad. In response to these suggestions the Secretary of State appointed the Citizenship Board of 1906, composed of the Solicitor of the State Department, the Minister to the Netherlands and the Chief of the Passport Bureau. The board conducted a study and late in 1906 made an extensive report with recommendations for legislation. Among the recommendations of the board were that expatriation of a citizen "be assumed" when, in time of peace, he became naturalized in a foreign state, engaged in the service of a foreign state where such service involved the taking of an oath of allegiance to that state, or domiciled in a foreign state for five years with no intention to return. Citizenship of the United States, Expatriation, and Protection Abroad, H. R. Doc. No. 326, 59th Cong., 2d Sess. 23. It also recommended that an American woman who married a foreigner be regarded as losing her American citizenship during coverture. Id., at 29. As to the first two recommended acts of expatriation, the report stated that "no man should be permitted deliberately to place himself in a position where his services may be claimed by more than one government and his allegiance be due to more than one." Id., at 23. As to the third, the board stated that more and more Americans were going abroad to live "and the question of their protection causes increasing embarrassment to this Government in its relations with foreign powers." Id., at 25. Within a month of the submission of this report a bill was introduced in the House by Representative Perkins of New York based on the board's recommendations. Perkins' bill provided that a citizen would be "deemed to have expatriated himself" when, in peacetime, he became naturalized in a foreign country or took an oath of allegiance to a foreign state; it was presumed that a naturalized citizen who resided for five years in a foreign state had |