America’s waterways were once the superhighways of travel and communication. Coursing through a central line across the landscape, with tributaries connecting the South to the Great Plains and the Great Lakes, the Mississippi River meant wealth, knowledge, and power for those who could master it. In Masters of the Middle Waters: Indian Nations and Colonial Ambitions Along the Mississippi(Harvard University Press, 2019), Jacob Lee offers a new understanding of early America based on the long history of warfare and resistance in the Mississippi River valley. Lee, an Assistant Professor of History at Pennsylvania State University, traces the Native kinship ties that determined which nations rose and fell in the period before the Illinois became dominant. With a complex network of allies stretching from Lake Superior to Arkansas, the Illinois were at the height of their power in 1673 when the first French explorers—fur trader Louis Jolliet and Jesuit priest Jacques Marquette—made their way down the Mississippi. Over the next century, a succession of European empires claimed parts of the midcontinent, but they all faced the challenge of navigating Native alliances and social structures that had existed for centuries. When American settlers claimed the region in the early nineteenth century, they overturned 150 years of interaction between Indians and Europeans. Masters of the Middle Waters shows that the Mississippi and its tributaries were never simply a backdrop to unfolding events. We cannot understand the trajectory of early America without taking into account the vast heartland and its waterways, which advanced and thwarted the aspirations of Native nations, European imperialists, and American settlers alike. Ryan Tripp is adjunct history faculty for the College of Online and Continuing Education at Southern New Hampshire University.