Fletcher first arrived in Quebec on 20 October 1827, where he began attending the Reverend Daniel Wilkie's private school, and in 1832 he began studies at the Séminaire de Québec. He contracted cholera in 1832 during the 1826–1837 cholera pandemic and survived but lost his mother to the disease. On 21 October 1846, he married Henrietta Amelia Lindsay, who was the daughter of William Burns Lindsay Sr. and brother of William Burns Lindsay Jr., both of whom were clerks of the Legislative Assembly. Together, they had thirteen children, six of whom lived.
