If the Founders took Natural Born Citizen to mean just anyone born on American soil, why did they differentiate natural born from mere citizen when they wrote the Constitution? ... Prior to the fourteenth amendment, the Constitution discerns at least three types of citizenship, only one of which is naturalized citizenship. One is natural born citizenship (parents who are citizens and born on American soil, and mere citizenship derived from being born on American soil. A mere citizen can be born with dividied citizenship/dividied loyalties; a natural born citizen will not be born with divided citizenship since both parents are American citizens at the child's birth, natural born being derived in the special case of president and vice president from their parents as citizens of America and born on American soil.
Read it again. There are only two. Naturalized and natural born.
No other distinction.