Originally Posted by CosmicTang

many people are (were) born in the canal zone that were not granted citizenship. Only those born to American parents were granted US citizenship.

"In 1953, Congress passed legislation to specify the status of Americans born in the Canal Zone--and to exclude non-Americans born there from citizenship. Title 8, Section 1403 of the United States Code grants citizenship to those born in the Canal Zone with at least one parent who is a United States citizen. This differs from the provision in the Fourteenth Amendment which grants citizenship to all born in the United States, regardless of parental nationality."

http://en.wikipedia.org/wiki/Panama_Canal_Zone