(a) The provisions of paragraphs (c), (d), (e), and (g) of section
1401 of this title, and of paragraph (2) of section
1408 of this title, shall apply as of the date of birth to a person born out of wedlock if
(1) a blood relationship between the person and the father is established by clear and convincing evidence,
(2) the father had the nationality of the United States at the time of the persons birth,
(3) 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
(4) while the person is under the age of 18 years
(A) the person is legitimated under the law of the persons residence or domicile,
(B) the father acknowledges paternity of the person in writing under oath, or
(C) the paternity of the person is established by adjudication of a competent court.
(b) Except as otherwise provided in section 405 of this Act, the provisions of section
1401 (g) of this title 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.
