Henry David Thoreau wrote four full-length works, collected here in a single volume. 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" is at once a personal...