which old and well-known facts must, if possible, be so grouped as to explain the position of the section in American history. In spite of the difficulties of the task, there is a definite advantage in so large a view. By fixing our attention too exclusively upon the artificial boundary lines of the States, we have failed to perceive much that is significant in the westward development of the United States. For instance, our colonial system did not begin with the Spanish War; the United States has had a colonial history and policy from the beginning of the Republic; but they have been hidden under the phraseology of "interstate migration" and "territorial organization." The American people have occupied a spacious wilderness; vast physiographic provinces, each with its own peculiarities, have lain across the path of this migration, and each has furnished a special environment for economic and social transformation. It is possible to underestimate the importance of State lines, but if we direct our gaze rather to the physiographic province than to the State area, we shall be able to see some facts in a new light. Then it becomes clear that these physiographic provinces of America are in some respects comparable to the countries of Europe, and that each has its own history of occupation and development. General Francis A. Walker once remarked that "the course of settlement has called upon our people to occupy territory as extensive as Switzerland, as England, as Italy, and latterly, as France or Germany, every ten years." It is this element of vastness in the achievements of American democracy that gives a peculiar interest to the conquest and development of the Middle West. The effects of this conquest and development upon the present United States have been of fundamental importance.