This work investigates the primary drivers and documented records of the American westward expansion between 1803 and 1879. Richard A. Bartlett, an established historian of the American frontier, synthesizes historical narrative with primary source documentation to examine the individuals and expeditions that facilitated the movement toward the Pacific Ocean. The text provides a structured overview of the socio-political motivations and the technical contributions of those who mapped and recorded the territory.

Experts recognize this text as a useful introductory survey for understanding the visual and historical documentation of the American frontier. Readers frequently note the clarity of the organizational structure in separating narrative history from the technical and artistic records of the period.