Of all the individuals who helped open the American West to U.S. settlement and territorial expansion, none today receives less acclaim relative to his impact than John Charles Frémont. Western explorer, Union general and the Republican party’s first presidential candidate, Frémont was one of the most famous Americans of his day, but his place in history is overshadowed by those whose achievements in similar fields eclipsed his own, such as Lewis & Clark, Ulysses S. Grant and Abraham Lincoln.

In his new biography, Pathfinder: John Charles Frémont and the Course of American Empire (Hill and Wang, 2002), Tom Chaffin plots the course of Frémont’s life and attempts to provide answers for why a man whose star of fortune, at times appearing destined to take its permanent place in the constellation of 19th century American heroes, lost its brilliance but never quite fell. Over some 500 pages, Chaffin tracks Frémont from his birth in Savannah in 1813, through the Western expeditions that brought him fame in the 1840s, to the 1856 presidential candidacy and subsequent military service in the Civil War, and finally through the failed political career and botched business dealings that led up to Frémont’s death in 1890.

Though just published in December, Pathfinder already has gone into a second printing and has been picked up by the Book of the Month and the History Book clubs. Publisher’s Weekly called it “a superb biography [that] creates a deeply nuanced portrait of a man of many parts,” and the San Francisco Chronicle praised Chaffin as a “very thorough and uncommonly graceful historian.”

Appropriately, Pathfinder focuses on the facet of Frémont’s life that will endure: his three federally sponsored Western expeditions, undertaken between 1842 and 1849, that through their published accounts captivated a nation and helped ensure America’s “empire”—a word whose meaning, Chaffin points out, has evolved through history—would encompass both shores of the continent.

“Frémont’s the one who puts mapmaking of the West on a scientific foundation,” said Chaffin, lecturer in journalism and history. “Beyond popularizing the West and revealing it to be more ecologically variegated than previously believed—and more amenable to permanent human settlement and agriculture—he also compelled Americans to reimagine the West; and, in the process of reimagining the West, to reimagine America itself.”

Before Frémont’s travels, much of the West was a mystery to all save a small population of trappers and the most courageous of settlers. Lewis & Clark’s journals were not published until a decade after their 1804–06 expedition, and even then the book sold slowly. Nearly all the country believed the land between the Missouri River and the Rocky Mountains to be a vast wasteland, unsuitable for settlement.

Frémont, blazing few trails himself (the “Pathfinder,” as he came to be called, followed mostly established Indian and trappers’ routes) but the first to document his travels with any degree of geographical precision, returned East with tales of a land of spectacular beauty, imposing mountain peaks—and fertile soil.

Earning a reputation equal to the fictional frontiersman creations of Washington Irving and James Fenimore Cooper, Frémont became a dashing, romantic figure for a nation eager to project its dreams westward.

Unfortunately for Frémont, his success in cartography did not translate to the business, military or political arenas. He already had been court martialed when the nascent Republican party, hoping to capitalize upon Frémont’s reputation and his anti-slavery views, tapped him as its first presidential candidate in 1856. His defeat by Democrat James Buchanan foreshadowed a long, steady descent for Frémont that, though punctuated by moments of political and financial success, ended ignominiously for the once-celebrated explorer who died hoping his memoirs would erase lingering stains of political and entrepreneurial corruption.

“Frémont the man has dropped from memory, but his name persists all over the landscape, in rivers, towns, counties, mountains, shopping malls, branches of public libraries,” Chaffin said. “People who live on, say, ‘Frémont Street’ often don’t know who he is. But among those who do, Frémont’s name still prompts strong reactions, both positive and negative. He’s still a controversial figure after all these years.

“Above all else,” Chaffin continued, “Frémont possessed a jeweler’s eye for assaying landscapes and comprehending how mountains, rivers, deserts, lakes and valleys cohere into a continental whole. And his vision of the United States as a continental nation gave American writers and thinkers a new template for writing and thinking about America. In this regard, Frémont was an enormous influence on Whitman, Longfellow and other writers of that age who were self-consciously working to shape a new sort of American nationalism and American self-image.”