Valley of Opportunity is an important book. Like the region it analyzes, it moves across boundaries, providing new vistas while connecting arbitrarily divided terrains.(Journal of American History) Mancall merits commendation for his attention to ecological as well as economic revolutions, his incorporation of Indians into the transition question, and his reminder that conquest left a continental legacy.(Western Historical Quarterly) Mancall shows how valley residents tied themselves into the commercial network that linked North America to Europe. Some people prospered in this valley of opportunity, many did not, and their fates often were determined less by their own endeavors than by the forces of the Atlantic economy that reached into their world.(Ethnohistory) Mancall's central argument is that the 'economic culture' of the backcountry was shaped by a complex interaction of physical environ- ments, local societies, and powerful developers—an encounter decided on the terms of the latter group, the agents of the greater Atlantic economy. Mancall's is a sober and sobering thesis, underscoring the power of capital on the eighteenth-century frontier.(William and Mary Quarterly)