Recounting his 1897-98 Klondike Gold Rush experience Jack London stated: "It was in the Klondike I found myself. There nobody talks. Everybody thinks. There you get your perspective. I got mine." This study explores how London's Northland odyssey - along with an insatiable intellectual curiosity, a hardscrabble youth in the San Francisco Bay Area, and an acute craving for social justice - launched the literary career of one of America's most dynamic 20th-century writers. The major Northland works - including The Call of the Wild, White Fang, and "To Build a Fire"- are considered in connection with the motifs of literary Naturalism, as well as in relation to complicated issues involving imperialism, race, and gender. London's key subjects - the frontier, the struggle for survival, and economic mobility - are examined in conjunction with how he developed the underlying themes of his work to engage and challenge the social, political, and philosophical revolutions of his era that were initiated by Darwin, Marx, Nietzsche, and others.