I would suggest your ancestor is Peter Narcisse Letourneau, b. 10 April 1821 in Detroit; m. 21 March 1843 in Detroit to Isabella Desnoyers, b. 1825, dau. of Louis Desnoyers and Francoise Petit. Peter is the son of James Letourneau and Mary Ann Duchesne. E-mail me if you need more. My information came from Denissen's, "French Families of the Detroit River Region".

Mike LaForest
mjlaforest@earthlink.net