In Dreamers and Defenders Douglas H. Strong relates the triumphs and defeats of twelve environmentalists from Henry David Thoreau to Barry Commoner. Their biographies form the dramatic and ongoing story of the conservation movement in America. Beginning with Thoreau, Frederick Law Olmsted, and George Perkins Marsh, Strong shows that conservation enjoyed the support of a few writers and scientists even in the heyday of land development in the mid-nineteenth century. Later chapters are devoted to John Wesley Powell, who after the Civil War attempted to introduce enlightened land policies in the...