Dédier was born November 23, 1831, the son of Marin Comeau and Madeleine Maillet. He built a house near Saint-Alphonse, then called Chéticamp de Clare or Petit Chéticamp. He married Elisabeth Thibodeau on November 11, 1862. They had thirteen children together. A farmer and a lumberman, he was reported a stern and disciplinary man. They took Jérôme into their household upon the death of his elder sister Victoire Comeau and her husband’s departure from Clare. Even with the small weekly stipend they received for Jérôme’s upkeep, their were never rich. The 1871 census shows him to have a slightly larger farm than his neighbours, owning about 250 acres, including pastures, dyked marshland and woodland. They grew oats, potatoes and hay, and owned cattle, sheep and pigs. Dédier cut wood on his lands for heating and cooking, and used the hay he grew to feed their farm animals, which they slaughtered for their own consumption.