Mackenzie, Alexander, 1822–92, Canadian political leader, b. Scotland. Emigrating (1842) to Canada, he worked first as a stonemason in Kingston, Ont., and then as a builder and contractor in Sarnia. In Lambton he became editor (1852) of a Liberal newspaper. Elected (1861) to the Canadian Legislative Assembly, Mackenzie supported the confederation movement and the Liberal leader, George Brown. A member of the first dominion House of Commons (1867), Mackenzie headed the Liberal opposition to Sir John A. Macdonald's government; upon its fall (1873) as a result of the Pacific scandal he became the first Liberal prime minister of the dominion. In 1878, Macdonald came back into power, and Mackenzie, who remained in Parliament until his death, led the Liberal opposition until 1880. During his ministry the courts and provincial governments were strengthened, trade expanded, and immigration, especially to the western provinces, was encouraged.
See his life and times by W. Buckingham and G. W. Ross (1892, repr. 1969).