Millen's papers fall into three series: records from his legal career, records from his business career, and files concerning McGill. Documenting his career as a lawyer are 8 cm of correspondence regarding lawsuits and court cases, interspersed with some personal matters, e.g. the affairs of the Graduates' Society (1930-1934). Appointment diaries cover the years 1931-1933. The bulk of this archive is a group of business files (1949-1970), containing accounting reports and financial statements for John Millen and Co., some miscellaneous correspondence, and clippings concerning business and politics. Millen's work for the Graduates' Society and as a McGill governor is the subject of files of correspondence, memoranda, minutes and printed material, largely on fund raising and athletics (1930-1972). See also JOHN MILLEN & CO., SECTION V. BUSINESS AND ECONOMY