Frémont, sometimes called "The Pathfinder" and "The West's Greatest Adventurer" as well as "A Man Unafraid", traversed more of the American West than any other explorers, including Meriwether Lewis and William Clark. Although he was not primarily a literary figure, his writings were crucial to the opening up of America's frontier lands. His geographical discoveries became intertwined with controversial decisions made during a long and tempestuous career, giving rise to almost incessant quarrels recorded in the public press and in books and articles by and about him. To this day controversy concerning him seems unending.

John Charles Frémont was born on 21 January 1813 in Savannah, Georgia, the illegitimate son of a French-Canadian wanderer, Charles Frémon, and a Virginian mother of upper-class origins, Anne Whiting Pryor. His father died or disappeared when the boy was only five years old. With the financial aid of...