Series consists of the official correspondence produced during the Rt. Hon. John Diefenbaker's tenure as Prime Minister of Canada from June 1957 to April 1963. The numbered correspondence touches upon virtually every aspect of Diefenbaker's prime ministerial career, including both his achievements and defeats. It documents all aspects of Canadian policy under the Diefenbaker government including the Northern Vision, a programme of national development that promoted a dynamic and independent Canada, the National Agricultural Programme, the opening of the St. Lawrence Seaway as well as the cancellation of the Avro CF 105 Arrow project, the nuclear warheads controversy and the Coyne affair. It also documents Canada's involvement in international affairs, such as Canada's role in the Commonwealth and the Cuban Missile Crisis to name only two. In addition, the papers shed light on the careers of Diefenbaker's cabinet ministers, senior civil servants and the provincial premiers of the era, and the myriad of issues which concerned Canadians during the 1957-1963 period, including four federal elections.
The series reflects the order of the records as filed in the PMO (Prime Ministers Office). The PMO under Diefenbaker was divided into five main sections: administration, correspondence, filing, reference, and the senior secretariat. The PMO used a subject filing system based on a decimal classification system that was co-designed by the administrator of Diefenbaker's filing section, Gordon Hetherington. The system utilized ten broad subject areas or classes: General, Defence, Economy, Government, Law, Resources and Development, Social Welfare, Trade and Commerce, World Relations, and lastly, History, Geography and Biography. Each broad category could be further subdivided into smaller, more subject specific, divisions. The finding aid provides a detailed list of the classification system.
While generally efficient and comprehensive, the PMO classification system was not without anomalies nor exempt from periodic breakdowns. The former derived largely from the subjective factor in the system, namely, the various staff members who, on a daily basis, were obliged to assign subject classifications to the huge volume of correspondence that deluged the PMO filing section. For instance, correspondence regarding an issue like nuclear weapons could be classified in at least four different ways: 154.3 Atomic Armament, 154.4 Nuclear Stockpiling, 806 Disarmament or 844 Peace. As for system breakdowns, these tended to coincide with events like elections or major public debates, both of which generated so much correspondence that the PMO staff could not fully process the material. This correspondence is now located in Series VIII, PMO Unnumbered Correspondence. Researchers should consult both Series VI and Series VIII when searching for official Diefenbaker correspondence.
The PMO numeric classification system was substantially enhanced by an indexing system used by the PMO filing section. In addition to classifying documents in numeric subject files, file clerks prepared cross-reference sheets for relevant files and maintained an extensive card index which provided both nominal and subject access to the papers. While not absolutely comprehensive, the card index represents an extremely valuable finding aid. In addition to indexing most of the documents in the PMO Numbered Files, the index makes occasional reference to two other series, Series VII, Reference Series and Series XII, Personal and Confidential Series. Material transferred to Series VII is indicated by references to Room 137, whereas that transferred to Series XII is sometimes described as "filed in the safe". The originals of many VIP letters were also transferred to Series XII. The PMO card index is available on microfilm reels M-8459 to M-8503 and is divided into four sections: Nominal, 1957-1963; Subjects, 1957-1958; Subjects, 1958-1963, and Restricted Nominal and Subject cards 1957- 1963. A microfilm conversion list for the card indexes is available as part of the finding aid.
As well as arranging material by numeric subject classification, the Diefenbaker PMO staff also processed the papers according to security considerations. Most documents were assigned general classifications; however, a sizeable number of files received one of four restricted classifications: Official, Confidential, Secret or Top Secret. As a result of both their security classification and the large number of government documents which they contained, these Numbered restricted files were screened by government departments in order to avoid the release of sensitive material. The files removed for screening were also microfilmed separately from the general files. However, most of these files were eventually designated open and were returned to their original volumes following the completion of microfilming.
Due to the fact that many of the cards found in the PMO card index provide a summary of restricted items, the index was also screened for substantial references to restricted documents. As a result of this process, some cards were removed and microfilmed separately on reel M-8503.
Available on microfilm reels M-7788 to M-7961, M-8451 to M-8503, M-8849 to M-8928.
