In your fifth generation, so you have anything on their son Jean Desilet Mousseau who married Catherine Lavoie and then Marie-amable Ricard on March 1, 1802 in St. Jacques? We know that the children of this (second) marriage on March 1, 1802 in St. Jacques were:
1. Marie Madelaine b. 26 March 1802St. Jacques 2. Eustache 1804-1813St. Jacques 3. Abraham 1807-1810St. Jacques 4. Michel Mousseauxbapt. July 4 1811 St. Jacques
It sort of looks like this family may have disappeared form St. Jacques after 1813. I am trying to find more about the Michel Mousseau listed above. I think he was my ancestor who moved to Long Sault Island, in the St. Lawrence River near Cornwall, Ontario and Massena NY and married Adelaide Melott in 1840. Thanks for any information.