The Letters of Theodore Roosevelt constitute a major contribution to the field of American history and literature. At the same time, they present an autobiography of matchless candor and vitality. They are at once a mine of information for the historian, a case study in astute and vigorous political leadership, and a delight to the general reader. All the letters needed to reveal Roosevelt's thought and action in his public and private life are included, with appropriate editorial comment; and each is printed in its entirety.

In the letters of 1905–1909, Roosevelt's "big stick" carries increasing weight at home and abroad. These are the years of the fleet's cruise around the world, of trust-busting and railroad regulation and currency control, and the building of the Panama Canal. They include the Panic of 1907, "Nature Faking," conservation, the choice of a successor, and the bitter conflict between President and Congress in the closing days of the administration.