The evolution of the United States from thirteen struggling and rebellious colonies to the position of wealth and strength that it occupies in the twentieth century is one of the most fascinating stories that history affords. In a style that deftly captures the spirit and feverish excitement of events, Robert Silverberg chronicles the westward movement, from the initial impulses for expansion — embodied in the concept of "manifest destiny" — to approximately 1853, when the present boundaries of the continental United States were taking shape. The Lewis and Clark expedition, Texas fever, the California gold rush, the Mormon settlement of Utah — all are chapters in this great American story.