Although few remember their former significance, oysters were one of the largest U.S. fisheries at their peak in the late nineteenth century. As the fishery industrialized on-and offshore, oyster farms and canning factories spread along the Eastern Seaboard, with overharvesting becoming increasingly common. During the Progressive Era, state governments founded new agencies to cope with this problem and control this expanding economy. Regulators faced a choice: keep elaborate conservation systems based on common property rights or develop new ones with private, hatchery-stocked aquaculture farms. The tradition-preserving solution won, laying the groundwork for modern oyster management. The Aquatic Frontier explores the forms this debate took between 1870 and 1920 in law enforcement, legislative advising, natural science, and oyster cartography. Samuel P. Hanes argues that the effort to centralize and privatize the industry failed due to a lack of understanding of the complex social-ecological systems in place - a common dilemma for environmental managers in this time period and for fisheries management confronting dangers from dwindling populations today.