For all these reasons the difficulties of the United States in adjusting the life and ideals and institutions of the nation to the presence of foreigners are reduced in the case of the Scandinavians to a minimum. The Swedes, Norwegians, and Danes are not likely to furnish great leaders, but they will be in the front rank of those who follow with sturdy intelligence and conscience, striving to make the land of their adoption strong and prosperous,--"a blessing to the common man," according to the original vision of America seen by Sweden's great king Gustavus Adolphus. They will be builders, not destroyers; their greatest service will be as a mighty, silent, steadying influence, re-enforcing those high qualities which are sometimes called Puritan, sometimes American, but which in any case make for local and national peace, progress, and righteousness. CHAPTER XIV. CRITICAL ESSAY ON MATERIALS AND AUTHORITIES The term bibliography does not accurately or fully describe the materials upon which this study of the Scandinavians in the Northwest is based. To the printed sources of all sorts,--official reports of European and American governments, autobiographies, travels, and the like--and to a wide range of secondary works, there must be added much matter relating to the subject gathered by means of personal interviews, correspondence, and observations extending over a series of years. The Scandinavian press is an inexhaustible mine of source material; its information, in nuggets, flakes, and fine particles, must be sought for diligently, extracted, refined, and shaped; but it is the purest source material, nevertheless, comprising brief autobiographies, letters, personal opinions, description of surroundings and movements, and contributions to current discussion in politics, religion, and education. The county and local histories which multiplied rapidly between 1880 and 1895, and which have not yet ceased to appear, are not far from the borderland of source material. Their sketches of men and women and settlements, tho for the most part of a crude, innocent, laudatory type based upon brief personal interviews by canvassers and elaborated according to the varying size of the subscriptions of individuals, are almost indispensable for certain statistical purposes. The customary distinction between source material and secondary material is often hard to maintain, so recent is the Scandinavian immigration, and so numerous are the first-hand and second-hand accounts by contemporaries participating in or observing the phenomena under consideration. The Northern peoples settling in the United States have had no William Bradford for a historian, but the work of Norelius and Mattson is in a class similar to that of _Plimouth Plantation_.