Louisiana's Atchafalaya River Basin is one of the most dynamic and critical environments in the country. It sustains the nation's last cypress-tupelo wetland and provides a habitat for many species of animals. Endowed with natural gas and oil fields, the basin also supports a large commercial fisheries industry. Perhaps most crucial, it remains a primary component of the plan to control the Mississippi River and relieve flooding in New Orleans, Baton Rouge, and other communities in the lower river valley. The continuing health of the basin is a reflection not of nature, but of the work of the U.S. Army Corps of Engineers. With levee building and clearing in the nineteenth century and damming, dredging, and floodway construction in the twentieth, the basin was converted from a vast forested swamp into a designer wetland, where human aspirations and nature maintained a precarious equilibrium. Originally published by the U.S. Army Corps of Engineers primarily for internal distribution, this environmental and political history of the Atchafalaya Basin is an unflinching account of the transformation of an area that has endured perhaps more human manipulation than any other natural environment in the nation. Martin Reuss provides a new preface to bring us up-to-date on the state of the basin, which remains both an engineering contrivance and natural wonder. MARTIN REUSS is a senior historian in the Office of History of the U.S. Army Corps of Engineers. He lives in Woodbridge, Virginia.