"Walden" and Other Writings, edited by Brooks Atkinson and with an excellent introduction by Ralph Waldo Emerson, is a collection of Thoreau's major works, including additional nature writing and political essays such as "Civil Disobedience" and "A Plea for Captain John Brown." First published in 1937, the collection was republished in a new edition in 2000.

Essays: First and Second Series (1990), edited by Douglas Crase, collects the major essays of Thoreau's mentor and friend, Ralph Waldo Emerson. These essays were originally published in two separate volumes in 1841 and 1844, and they express philosophies and attitudes very similar to those found in Walden.

My First Summer in the Sierra (1911), by John Muir, is the most popular work of the famous conservationist and, along with Walden, is a classic American nature journal. Muir was just a young man in 1869, when he spent the summer helping...