High Quality Content by WIKIPEDIA articles! Sir John Alexander Macdonald, GCB, KCMG, PC, PC (Can), QC (11 January 1815 – 6 June 1891) was the first Prime Minister of Canada. The dominant figure of Canadian Confederation, his political career spanned almost half a century. Macdonald served 19 years as Canadian Prime Minister; only William Lyon Mackenzie King served longer.