The Desilets surname was "invented" in Quebec, so that's were the origin is. I have put together a fair size database on the Desilets family over the years. Your great-grandfather had siblings that I know of: - Edouard married to Eugenie Morin - Jane married to Alfred Moreau - Jean married to Celina Labrie
All were married in Berlin, NH
I have not however found the marriage information of their parents Louis Desilets and Philomène Routhier. And since I'd like to think I have most Desilets marriages that occured in Quebec, my feeling is that Louis Desilets and Philomène Routhier married in US. And until we find Louis's parents, we can't go up farther the tree. I'm still searching.
I'll e-mail you the records as I have them now on your line.