William Lyon Mackenzie was born in Dundee, Scotland, on March 12, 1795, and emigrated to Canada in 1820. His newspaper, the Colonial Advocate, made him the scourge of the Family Compact, the clique that governed Upper Canada; in the Type Riot of 1826, young Tory rioters smashed his press and threw his type into Toronto Bay — and Mackenzie sued and won. In 1834, York incorporated as the city of Toronto and elected him its first mayor.

Convinced reform would never come by ballots alone, Mackenzie raised a rebel force in December 1837 and marched down Yonge Street in the Upper Canada Rebellion. It collapsed within days; he fled to the United States, was jailed there, and returned under amnesty in 1849 to sit in Parliament again. He died in Toronto on August 28, 1861. His daughter Isabel became the mother of Prime Minister William Lyon Mackenzie King, who lies across the city in Mount Pleasant.