A 1900 census also lists Angelique Sam Jean Louis living with St ville. He also states that she was his cousin. How can an uncle be a cousin???

LaTour Genealogical Collection Says:

In the 1900 census, Marie Angelique Louis Sam is living with Jean St. Ville LeBlanc and his wife, Marie Onesia Jean-Louis.

Marie Angelique Louis Sam is the wife of the uncle of Marie Onesia Jean-Louis, Jean Baptist Marie Jean-Louis Simon.