This work investigates the rapid emergence of San Francisco and Denver as prototypical 'instant cities' that bypassed traditional developmental stages to become major urban centers in the American West. Gunther Barth, a historian specializing in the American West, utilizes primary source documentation and urban development records to argue that these cities represent a unique phenomenon in American history. He posits that the absence of a rural hinterland and the immediate influx of diverse populations created a distinct urban culture characterized by rapid social and economic integration. The book examines how these environments fostered a specific type of American urban identity that differed significantly from the slower, more organic growth patterns observed in Eastern cities.

Historians and urban scholars frequently cite this text as a foundational study for understanding the unique developmental trajectory of Western American cities. Readers often note the academic density of the prose, which provides a rigorous examination of the socio-economic factors that defined the frontier urban experience.