I guess I don't know for sure, but I could make some guesses for you.I would very much doubt that your Robillard family is connected to the Robillards in Quebec, and here's why I think that:
Claude Robillard and Marie Grondin in approximately the 1670's from France (I'm guessing because I don't have my notes in front of me at the minute) and their children's birthdates range from bef. 1673 to 1692 and none of them are named Charles.When I looked up your family, from what I can tell Louis, son of Charles and Marie Ouguenarde, was born around 1700 or so.This would mean that Charles was probably born 1670-1680 (approx.).So if was connected to the Robillards in Quebec, he would probably be the son of Claude and Marie.
Claude and Marie did have one son, Claude, which is the only one that's probably close to the right time period, etc. who was born before 1677 and married in 1701 to Angelique Cecire, so that's not even close.
But it's interesting because I didn't know there was another line of Robillards in Illinois!But I can definately keep my eyes out in case I run across any info. on them!
And I think...Port de Chartres is really Fort de Chartres, although I could be wrong.Seems I've seen that before though!