My mother is the eldest of eight Chastang children out of Chastang, Alabama. One of my cousins has done quite a bit of work in tracing the family lineage back to, I believe, Niles, France. Once I find the calendar he put together a few years ago, I will post it for you. I know there is only one family of Chestang/Chastang/Chastain in the United States and several of my cousins had been doing research. Hopefully, the information will help you connect some of the pieces you already have.