Is a child born in Mexico a US citizen if the child's father is a US citizen?
If both parents were US citizens and married before the birth,
the the child is automatically a US citizen; birthplace is
irrelevant. However, if only one parent was a US citizen at the
time of the birth , it gets a little trickier. It depends on when
the child was born (laws change), however since 1952, if the couple
was married before the birth and the father meets residency
requirements in the US then the child is a US citizen. Your best
bet is to consult an attorney who specializes in this.