This series consists of notes and drafts of speeches. MacMillan was a prolific writer on political and social subjects. Much of his work was written to be delivered by Sir Arthur Currie, who, both as a veteran and as Principal of McGill, was frequently called on to address Founder's Day gatherings as well as Armistice Day ceremonies. MacMillan also spoke at many affairs for which he received laudable reviews. Many of his notes and drafts are untitled and undated so that it not always possible to know if they were written for Sir Arthur or Dr. MacMillan, himself, as both men were veterans and connected with McGill.The detailed list of MacMillan's own notes in File 1057-2-39 gives some idea of the wide range of subjects about which he wrote.
This series consists of letters from Cyrus MacMillan to his brother, sister and mother during World War I, and 10 years of letters to his wife written mainly between 1925 and 1940 when he was travelling with various Federal Fisheries Commissions in the Maritimes as well as opening the Prince of Wales College in P.E.I. in 1933. Incoming correspondence includes letters from Sir Arthur Currie, Andrew MacPhail, Stephen Leacock and MacKenzie King. There are thank-you letters from recipients of speeches written for them, and congratulatory messages from various correspondents.There are some letters involving MacMillan's tenure at McGill including one from Principal Cyril James re-appointing him as Dean of Arts and Science in 1944. MacMillan, himself, wrote letters of recomendation for students.