§ 309 (8 USC 1409) Children born out of wedlock
The provisions of paragraphs (c), (d), (e), and (g) of section 301 [8 U.S.C 1401] , and of paragraph (2) of section 308 [8 U.S.C 1408] , shall apply as of the date of birth to a person born out of wedlock if—
a blood relationship between the person and the father is established by clear and convincing evidence,
the father had the nationality of the United States at the time of the person's birth,
the father (unless deceased) has agreed in writing to provide financial support for the person until the person reaches the age of 18 years, and
while the person is under the age of 18 years—
Except as otherwise provided in section 405 of this Act, the provisions of section 301(g) of this Act [8 U.S.C 1401(g)] shall apply to a child born out of wedlock on or after January 13, 1941, and before December 24, 1952, as of the date of birth, if the paternity of such child is established at any time while such child is under the age of twenty-one years by legitimation.
Notwithstanding the provision of subsection (a) of this section , a person born, after December 23, 1952, outside the United States and out of wedlock shall be held to have acquired at birth the nationality status of his mother, if the mother had the nationality of the United States at the time of such person's birth, and if the mother had previously been physically present in the United States or one of its outlying possessions for a continuous period of one year.