In the present volume I have kept before myself the importance of regarding American development as the outcome of economic and social as well as political forces. To make plain the attitude and influence of New England, the middle region, the south, and the west, and of the public men who reflected the changing conditions of those sections in the period under consideration, has been my principal purpose.

The limits of the volume have prevented the elaboration of some points well worthy of fuller treatment; and, by the plan of the series, certain aspects of the period have been reserved for other writers.

I desire to express my cordial appreciation of the friendly criticism and assistance I have received from the editor, Professor Hart. To Professor Carl R. Fish, Professor A. A. Young, and Dr. U. B. Phillips, my colleagues, I am indebted for a critical reading of several chapters. I have drawn on the manuscript sources possessed by Dr. Phillips for information on many points of southern history.

Several of the topics dealt with in the volume have been investigated by graduate students in my seminary; particularly I have profited by the papers of Professor Homer C. Hockett on the Missouri Compromise and the rise of Jacksonian democracy; of Mr. Royal B. Way, now instructor in history in Northwestern University, on internal improvements; and of Dr. W. V. Pooley and Mr. A. C. Boggess on the settlement of Illinois. Mr. S. J. Buck, my assistant in American history, prepared under my direction some of the maps, particularly those of congressional votes.

The map of western fur-trading posts in Captain Chittenden's excellent History of the American Fur Trade furnished the basis for the map of western posts and trails. In the construction of the map of highways and waterways, I have used the map of H. S. Tanner, 1825, and Hewett's American Traveller (Washington, 1825). From the maps in the Eighteenth Annual Report of the Bureau of Ethnology have been drawn the data for the map of Indian cessions. The editor kindly supplied the map of Russian settlements and claims.

For the portrait of Henry Clay, which forms the frontispiece, thanks are due to Mr. Charles Henry Hart, of Philadelphia, the owner of the life-mask made by J. H. Browere.