In the mid-nineteenth century, Thoreau recognized the importance of preserving the complex and fragile landscape of Cape Cod, with its weathered windmills, expansive beaches, dunes, wetlands, harbors, and the lives that flourished here, supported by the maritime industries and saltworks. One hundred years later, the National Park Service--working with a group of concerned locals, then-senator John F. Kennedy, and other supporters--took on the challenge...