I had my numbers wrong. 14/19 years of age, not 16/21, nevertheless the result is the same.
8 U.S.C. § 1401 (g):
“a person born outside the geographical limits of the United States and its outlying possessions of parents one of whom is an alien, and the other a citizen of the United States” before Nov. 14, 1986 is a natural-born citizen only if the citizen parent “was physically present in the United States or its outlying possessions for a period or periods totaling not less than ten years, at least five of which were after attaining the age of fourteen years” — the same rule that was in place in the early 1960s. See also United States v. Flores-Villar, 497 F. Supp. 2d 1160, 1162-64 (S.D. Cal. 2007) (taking the same view and concluding the change from ten years/five years to five years/two years only applied to people born after 1986), aff’d, 536 F.3d 990 (9th Cir. 2008) (so assuming but not discussing it in detail); Rico-Ibarra v. Mukasey, 281 Fed. Appx. 694, 695 n.1 (9th Cir. 2008) (not precedential).
Full:
8 U.S.C. § 1401(g): a person born outside the geographical limits of the United States and its outlying possessions of parents one of whom is an alien, and the other a citizen of the United States who, prior to the birth of such person, was physically present in the United States or its outlying possessions for a period or periods totaling not less than five years, at least two of which were after attaining the age of fourteen years: Provided, That any periods of honorable service in the Armed Forces of the United States, or periods of employment with the United States Government or with an international organization as that term is defined in section 288 of Title 22 by such citizen parent, or any periods during which such citizen parent is physically present abroad as the dependent unmarried son or daughter and a member of the household of a person (A) honorably serving with the Armed Forces of the United States, or (B) employed by the United States Government or an international organization as defined in section 288 of Title 22, may be included in order to satisfy the physical-presence requirement of this paragraph. This proviso shall be applicable to persons born on or after December 24, 1952, to the same extent as if it had become effective in its present form on that date;
The law in effect in 1961 was the 1952 Nationality and Immigration Act commonly called the McCarron - Walters Act.
http://library.uwb.edu/guides/usimmigration/66%20stat%20163.pdf
TTTLE III - NATIONALITY AND NATURALIZATION
CHAPTER 1 – NATIONALITY AT BIRTH AND BY COLLECTIVE NATURALIZATION
NATIONALS AND CITIZENS OF THE UNITED STATES AT BIRTH
Sec. 301 (a) The following shall be nationals and citizens of the United States at birth:
(1) a person born in the United States, and subject to the jurisdiction thereof;
Sec. 301 (a) (7) A person born outside the geographical limits of the United States and its outlying possessions of parents one of whom is an alien, and the other a citizen of the United States who, prior to the birth of such a person, was physically present in the United States or its outlying possessions for a period or periods totaling not less than ten years, at least five of which were after attaining the age of fourteen years;”
Obama born in Hawaii comes under Section 301 (a) (1).
Obama born in Kenya comes under Section 301 (a) (7).