What does the law say about someone born in a foreign country?
US citizenship flows to the child at birth (natural born citizen) if one of several conditions are met. These are identified by the subsections of Title 8 section 1401. Here is a summary:
A - born on US soil / jurisdiction regardless of parent citizenship
B - American native or other aboriginal tribe member
C - Born outside of US to US parents
D - Born outside the US to at least one US citizen parent who has been physically present in the US for at least 1 year
E - Born in an outlying position (territory)to a US citizen parent who has resided at least 1 year in the US at anytime prior to the birth of the child.
F - Person of unknown parentage found in the US under the age of 5
G - Person born to US Citizen parent who has resided at least 5 years in the US prior to the birth of the child
H - Person born before noon May 24, 1934 outside the US, who has a US Citizen mother who resided in the US
see details at: http://www.law.cornell.edu/uscode/text/8/1401