An early observer remarked that it was doubtful that organic life was anywhere more exquisitely adjusted to its environment "than in the marshes of the ocean shore." Yet through most of American history, coastal wetlands have been viewed as noxious regions, some good for recreation but most fit only for dredging and reclamation. Recently, however, ecologists have recognized the diversity and biotic fecundity of the nation's tidelands. Joseph Siry carefully traces the interplay among scientific knowledge, popular values, legal frameworks, and public policy in the development of a wetlands ecological ethic. He demonstrates how the 1968 National Estuary Protection Act reflects the fruition of a vision first expressed by Adam Seybert in 1798 and developed by such luminaries as Frederick Law Olmstead, George Perkins Marsh, Aldo Leopold, and Rachel Carson. Since 1945, Siry argues, growing anxiety over destructive industrialism, loss of wild seashores, and the need for coastal resources have produced wetlands protection. He describes, in language appealing to the lay enthusiast as well as the specialist, the nationwide estuarine sanctuary system that exists today as the result of a new ecological awareness.