Henry David Thoreau wrote four full-length works, collected here for the first time in a single volume. Subtly interweaving natural observation, personal experience, and historical lore, they reveal his brilliance not only as a writer, but as a naturalist, scholar, historian, poet, and philosopher. "A Week on the Concord and Merrimack Rivers" is based on a boat trip taken with his brother from Concord, Massachusetts to Concord, New Hampshire. "Walden," one of America's great books, is at once a personal declaration of independence, social experiment, voyage of spiritual discovery, manual of self-reliance, and masterpiece of style. "The Maine Woods" and "Cape Cod" portray landscapes changing irreversibly even as he wrote. The first combines close observation of the unexplored Maine wilderness with a far-sighted plea for conservation; the second is a brilliant and unsentimental account of survival on a barren peninsula in the face of hostile elements, historical change, and natural decay.