_Other Methods of Acquiring Citizenship._--Citizenship may be acquired sometimes in other ways than the method described above. Thus a foreign woman becomes a citizen by marriage to an American citizen, and the inhabitants of foreign territory annexed to the United States become citizens by virtue of their incorporation into the body politic. In this way the inhabitants of the Louisiana territory, acquired from France, became citizens. In the same way those of Florida, Texas, California, Alaska, and Hawaii became citizens, but not those of Porto Rico and the Philippines. Residents of Porto Rico, however, were made citizens of the United States by act of Congress in 1917. =How Citizenship may be Lost.=--As citizenship may be acquired in various ways so it may be lost by different acts. An American woman loses her citizenship by marriage to an alien. Acceptance of a commission in the service of a foreign country; if it involves the taking of an oath of allegiance to a foreign government, operates to divest one of his American citizenship. The most common mode by which citizenship is lost, however, is through voluntary removal from the country and naturalization in a foreign state. The right of the citizen to withdraw from the United States, renounce his allegiance, and acquire the citizenship of a foreign state, is declared by our law to be an inalienable right. Mere removal from the United States and the establishment of a residence in a foreign country, however, does not of itself operate to divest one of his citizenship. An American citizen may reside abroad many years for the purposes of business, education, or pleasure, and so long as he preserves an intention of returning to the United States he is not held to have abandoned his American nationality. In order to prevent foreigners from coming to the United States, acquiring our citizenship, and returning to their native country for the purpose of living there without being subject to the burdens and obligations of military service, the law declares that a naturalized American who returns to his native country and resides there for a period of two years will be presumed to have abandoned his American citizenship, and unless he can show an intention of returning to America he will be considered as no longer being a citizen.