Series consists of correspondence from William Lyon Mackenzie King to his nephew Arthur King, also to Arthur's wife Kathleen Marion King, written between January 8, 1923 and July 5, 1950. Although Mackenzie King's first letters are directed towards the interests of a growing boy, over the years he stays involved in Arthur's progress through school, university and ultimately in the workplace. He mentions his own activities although often not in detail, sends thank you letters and holiday greetings. He gives Arthur advice on his career, mentions books of interest, and talks about politics, friends, family and visitors to Kingsmere.
Arranged chronologically.

Materials created by members of the Liberal Fourteenth Canadian Ministry with Prime Minister Right Honourable William Lyon Mackenzie King (September 1926 – August 1930). Includes materials related to different official events and addresses.

Scrapbooks and related materials created or accumulated by Hon. Dr. James Horace King (Minister during Hon. W. L. Mackenzie King Ministries). Scrapbooks contain photographs, correspondence, and newspaper clippings related to Canadian politics of the 1920s and 1930s.

Materials created by the Canadian Liberal Party during Conservative Ninth Canadian Ministry with Prime Minister Right Honourable Sir Robert Laird Borden (October 1911 – October 1917) and Unionist Eleventh Canadian Ministry with Prime Minister Right Honourable Arthur Meighen (July 1920 – December 1921).

Materials created by members of the Liberal Party of Canada and the Liberal Sixteenth Canadian Ministry with Prime Minister Right Honourable William Lyon Mackenzie King (October 1935 – November 1948). Includes materials related to political campaigns, different official events, and addresses.