8 U.S.C. § 1409 — Children born out of wedlock

(a) Sections 1401(c), (d), (e), and (g), and section 1408(2), apply from birth to a person born out of wedlock if: (1) clear and convincing evidence establishes a blood relationship with the father; (2) the father was a United States national at the person’s birth; (3) unless deceased, the father has agreed in writing to support the person financially until age 18; and (4) before the person turns 18, the person is legitimated under the law of the person’s residence or domicile, the father acknowledges paternity in a sworn writing, or a competent court establishes paternity. (b) Except as section 405 of this Act provides otherwise, section 1401(g) applies from birth to a child born out of wedlock on or after January 13, 1941, and before December 24, 1952, if legitimation establishes paternity while the child is under 21. (c) Despite subsection (a), a person born after December 23, 1952, outside the United States and out of wedlock is considered to have acquired at birth the nationality status of the mother if she was a United States national at birth and had previously been physically present in the United States or an outlying possession continuously for 1 year.