As I understand it, the idea that the word "creole" means a person of partial black ancestry is pretty recent. (I remember reading an article about a dating service that felt it had to tell its southern users that "creole" and "cajun" in personal ads were taken by nonsouthern users to mean part black-think that article was on FR.) In the 18th century , 'creole' meant a colonial of mixed Spanish and/or French ancestry-not African. Some creoles would indeed be part African or part Indian as well as French or Spanish ...but the word did not automatically mean part African, as the writer seems to believe. Napoleon referred to his first empress Josephine as "my little creole", and he didn't mean she was what he would have called a "Negroe" (preffered 18th century spelling.) So maybe Hamilton was part-black, maybe not-but references to his "creole" ancestry aren't proof.
In most dictionaries, the first definition of "creole" is something along the lines of "a person of European descent, esp. French or Spanish, born in Central or South America, the West Indies, or the United States Gulf region."
The definition involving mixed race ancestry is usually 4th or 5th.
I noticed that in the article as well.
Creole and Cajun has more to do with French ancestry than African.