That is because at the time the Indians were living on their own Indian Nations which were considered separate sovereign nations and thus not within the jurisdiction of the US of A. When the US territories expanded and the US couldn't pretend that the Indian reservations were really viable sovereign states, (plus a bunch of other admin reasons) they made them citizens and Poof! The 14th applied to them.
Did you guys sleep thru Civics class?
Did you guys sleep thru Civics class?