[grigjd3]

It is an assumption of ignorance on a massive and universal scale that is beyond reasonable. There is too many people involved to assume this was not considered. It's the same problem as assuming the moon landing was faked. The position that noone involved considered birthright centizenship beyond slavery is ludicrous. All those state legislatures, all those senators, all those house representatives, all their staffs plus the best legal minds available to the office of the president and your claim is not a single one of them realized birthright citizenship would apply to people who weren't former slaves? That is a ludicrous amount of doubt in human imagination.

EDIT: In fact in 1860, the us census measured 4.1 million people not born in the United States. Is your claim honestly that while the census actively measured this, not a single person realized what birthright citizenship would mean for the children of those 4.1 million non-natives?