Inquiry into the subject of annexation presents several knotty problems. The most daunting of these, the questions of the motivation of men and the reliability of materials, have already been described in the preface. Another difficulty was the great variety of possible sources of information and the relatively sparse and widely scattered facts to be found in any one of them, with a few exceptions to be noted below. Understandably, annexation was not a popular topic nor a frequently mentioned one in Canada. The author has combed the likely, and a good many of the unlikely, sources. The law of diminishing returns and the restrictions of time have necessarily limited the search. Doubtless, other newspapers and collections of correspondence would have yielded some additional data, but a considerable amount of panning would be necessary for every nugget washed out, and in all probability, these would do no more than add confirmatory detail to the narrative already established. Even in the most fruitful sources, there are many and stretches of six, eight, even twelve months when letter files or newspaper volumes do not yield a single item of applicable information.
Within the bounds of these qualifications, certain materials may be identified as the essential bases for this study, and the most important of these are the manuscript sources, particularly the ones to be found in the Public Archives of Canada. Here the enormous, but carefully divided, collection of Sir John A. Macdonald Papers was indispensable. There is at least some information in many of its numerous volumes, but the most important were those on Nova Scotia Affairs, Governor-Generals' Correspondence, Commercial Union, General Elections, and the Letter Books for the years 1867 to 1871 and 1887 to 1891.