Earnscliffe
This was the home of the Right Honourable Sir John A. Macdonald, P.C., G.C.B., M.P., Chief Architect of Confederation. Sir John was the first Prime Minister of the Dominion of Canada and headed the government from 1867 to 1873 and from 1878 to 1891. This house was built in 1855-57 by John MacKinnon and rented by Sir John in 1870-71 and in 1882. He bought it in 1883 and lived here until his death on June 6, 1891.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.