The career of John Charles Fremont (1813-90) celebrates and ties together the full breadth of American expansionism from its eighteenth-century origins through its culmination in the Gilded Age. Tom Chaffin's new biography demonstrates Fremont's vital importance to the history of American empire, and his role in shattering long-held myths about the ecology and habitability of the American West. As the most celebrated American explorer and mapper of his time, Fremont stood at the center of the vast federal project of Western exploration and conquest. His expeditions between 1838 and 1854 captured the public's imagination, inspired Americans to accept their nation's destiny as a vast continental empire, and earned him his enduring sobriquet, the Pathfinder. But Fremont was more than an explorer. Chaffin's narrative includes Fremont's varied experiences as an entrepreneur, abolitionist, Civil War general, husband to the remarkable Jessie Benton Fremont, two-time Republican presidential candidate, and Gilded Age aristocrat. Chaffin brings to life the personal and political experiences of a remarkable American whose saga offers compelling insight into the conflicts, tensions, and contradictions at the core of America's lust for empire and its conquest of the trans-Missouri West.