Some children although born in the United States are not subject to American jurisdiction. The children of a foreign ambassador, serving in the United States, are for this reason not citizens, even though born here. Children born on board a foreign warship in an American harbor are not deemed to be “subject to the jurisdiction” of the United States. But with a few unimportant exceptions of this sort all persons born in the United States are born within its jurisdiction, and hence are citizens by birth. One may be an American citizen by birth, moreover, without having been born in the United States. The children of American parents, even though born outside the territory of the United States, have the right to claim this citizenship. Children of American parents, born on the high seas, or on American war vessels in foreign ports, or children of American ambassadors born abroad, are citizens of the United States by virtue of their parentage. Children of American parents, born on foreign soil, have the right to choose between American citizenship and citizenship of the country in which they were born. Footnote 21: On rather rare occasions a large body of people, not citizens by birth, have become citizens of the United States by what is called collective naturalization. When Louisiana (1803), Florida (1819) and Alaska (1867) were acquired, for example, the treaties which provided for their acquisition stipulated that all inhabitants of these territories should be admitted to American citizenship without becoming individually naturalized. On the other hand, when Porto Rico and the Philippine Islands were ceded to us by Spain in 1898 there was no such provision. In the case of the Porto Ricans, citizenship was conferred by an act of Congress in 1917; in the case of the Filipinos the full status of American citizenship has not yet been granted. The Filipinos are called “nationals” of the United States, which means that they have the protection of the federal government, but are not entitled to all the other privileges and immunities of citizenship as provided in the constitution. Collective naturalization may thus be provided for by treaty or granted by act of Congress. Footnote 22: The leisure hours of pupils may also be utilized to secure excellent lessons in good citizenship. Unfortunately they are not always so used. Many of the recreations which are now popular with the young people of the United States afford neither physical exercise nor mental inspiration, neither do they conduce to the strengthening of character. Footnote 23: