William Lyon Mackenzie was a Scottish-born Canadian-American journalist and politician. He founded newspapers critical of the Family Compact, a term used to identify elite members of Upper Canada. He represented York County in the Legislative Assembly of Upper Canada and aligned with Reformers. He led the rebels in the Upper Canada Rebellion; after its defeat, he unsuccessfully rallied American support for an invasion of Upper Canada as part of the Patriot War. Although popular for criticising government officials, he failed to implement most of his policy objectives. He is one of the most recognizable Reformers of the early 19th century.