William Lyon Mackenzie was a Canadian journalist, politician, and a key figure in the early 19th-century reform movement in Upper Canada, now Ontario. Born on March 12, 1795, in Scotland, he immigrated to Canada in 1820. Mackenzie became known for his outspoken criticism of the ruling elite and advocated for democratic reforms, including responsible government. In 1837, he led the Upper Canada Rebellion against the colonial government, seeking to address grievances related to political corruption and lack of representation. Although the rebellion was unsuccessful, Mackenzie's efforts contributed to the eventual push for reform in Canada, influencing the development of Canadian democracy.