About Mackenzie King:
William Lyon Mackenzie King was the dominant Canadian political leader from the 1920s through the 1940s. He served as the tenth Prime Minister of Canada from December 29, 1921, to June 28, 1926; from September 25, 1926, to August 7, 1930; and from October 23, 1935, to November 15, 1948. A Liberal with 22 years in office, he was the longest-serving Prime Minister in Canadian history. Trained in law and social work, he was keenly interested in the human condition (as a boy, his motto was "Help those that cannot help themselves"), and played a major role in laying the foundations of the Canadian welfare state.