John Barrett McGann was born in Kilkenny, Ireland, in 1810. He trained as a land surveyor and then taught in a public school for 14 years. He left Ireland for America in 1854 and became interested in the education of deaf-mute children. He moved to Toronto as a teacher in 1855 and by 1858 was running a school for deaf children. The school closed in 1864 and McGann reopened it at Dundurn Castle in Hamilton. Its funding was precarious and in 1870 the Government of Ontario took over responsibility for the school at new premises in Belleville, Ontario. McGann was the resident superintendent of the Ontario Institute for the Education of the Deaf and Dumb in Belleville from 1870 until his death in January 1880. He was buried in the Belleville Cemetery.