Perilous Waters examines the history of wetland drainage in America, a story the author accurately assesses as “overlooked,” especially when compared to other facets of agricultural, environmental, and political history (p. 3). Wetland drainage was “one of the most consequential and transformative episodes of landscape modification and water engineering in US history,” yet has been “marginalized as a minor footnote in American environmental and political history” (p. 3). Perilous Waters makes a valuable contribution to this overlooked history. This book is primarily a political history of federal and state efforts to facilitate drainage, with a more local focus on the Red River Valley in Minnesota and North Dakota. Carleson argues that drainage was central to westward migration, the expansion of industrial farming, and the construction of the state authority over natural resources. As Carlson argues, drainage was indispensable to “the expansion of settler agriculture,” yet has “wallowed in historiographical backwards” (pp. 8–9).

The book is arranged chronologically, but its geographic scale shifts back and forth from the local to the national. Carlson’s primary goal is to show that local, state, and federal governments sponsored drainage projects to facilitate settler colonization and capitalist agriculture. To accomplish this goal, some chapters more narrowly focus on development in the Red River Valley while others examine a broader sweep of history or the actions of the federal government.

Chapter one, for example, examines the ancient Greek roots of western attitudes toward wetlands. Specifically, Hippocratic ideas about how wetlands caused miasmas were adopted by European Enlightenment figures. These ideas were then exported to the United States, where they fused with racist assumptions about Native Americans and African Americans. Carlson shows how both groups beneficially used wetlands while white settlers saw these places as obstacles to tillage. Chapter two maintains this broad national focus as it examines state and federal drainage efforts in the antebellum era. By far the most important elements of this story were the Swamp Land Acts of 1849, 1850, and 1860. These gave states title to federal swamp lands on the condition that states be responsible for their drainage. The implications of these laws were enormous. They limited federal involvement and responsibility for drainage and effectively made drainage a state and local responsibility.

The book’s next two chapters drill down to the local level to illustrate how drainage policies played out on an actual landscape: the Red River Valley in Minnesota. After the Civil War, this inundated region was flooded with settlers. Private drainage efforts by a local railroad magnate failed to drain lands, partly because neither ecological knowledge about these lands nor engineering expertise in drainage had been developed. Next, settlers and railroad companies looked to the state government. The failure of private efforts “primed settlers to accept an expansive vision of environmental governance and social organization that elevated expertise, comprehensive planning, technological solutions, and bureaucratization” (p. 93). The federal government continued to play a role as well, not by financing and directing drainage, but by surveying wet and flooded lands and by providing expertise.

Chapter five’s narrative moves back to the federal level by focusing on Nathaniel Shaler, a USGS bureaucrat who took the lead in studying drainage. Not surprisingly, this Progressive reformer was a vocal eugenicist. To Shaler, draining wetlands was a way to more efficiently use nature’s resources. Drainage would provide white settlers with reformed lands taken from native peoples. Shaler’s views of drainage were consistent with those of other Progressive conservationists; his racial views were directly in line with the long history of settler colonialism in the United States. Shaler’s work on drainage helped to build momentum for federal intervention in the Red River Valley into the early twentieth century. Local representatives worked to “put the federal government in charge of draining northern Minnesota,” but their efforts largely failed (p. 123). The federal government continued to mostly operate as an advisory body that disseminated knowledge and expertise. As Carlson writes, the federal government “proved far more skilled at dispersing power than wielding it in centralized bureaucracies” (p. 150). The book’s final chapter examines how the federal government encouraged states and local governments to establish drainage districts and drainage boards. Federal experts advised these boards, which drained wetlands. By 1920, these local bodies controlled 65.5 million acres of land.

Wetland drainage is often associated with large swamps like the Everglades, but Carlson shows how drainage was central to American agricultural and settler colonization, as well as to ethnic cleansing and Progressive reform. In the introduction, Carlson distinguishes between farm drainage and swamp drainage. This work is less concerned with the large-scale drainage of immense wetlands, a topic historians have written about, and focuses more intently on farm drainage, efforts to drain existing farms and make them more productive. This focus on farm drainage is a needed addition to this broader historiography.

A major throughline of Carlson’s work is the relationship between drainage and race. Government drainage efforts went hand in hand with settler colonialism and the removal of native peoples from their lands. Carlson is highly attentive to these points throughout his narrative and at several points brings native voices into this work. However, this book does not examine in any detail the pre-Columbian ecology of the Red River Valley. Neither does it provide much detail on native uses of the land or native life in the valley before Anglo settlement. These analyses are beyond the goals of the book, which are focused on the politics of drainage. Consequently, the natural world itself is mostly a mere setting for these political battles. Despite this minor criticism, Perilous Waters makes valuable contributions to the history of drainage, agriculture, and swamps in America. Carlson’s work deftly explores the nuanced and uneven growth of America’s environmental-regulatory state in the context of agricultural drainage.