Henry D. Thoreau's classic A Week on the Concord and Merrimack Rivers is published now as a new paperback edition and includes an introduction by noted writer John McPhee. This work--unusual for its symbolism and structure, its criticism of Christian institutions, and its many-layered storytelling--was Thoreau's first published book.

In the late summer of 1839, Thoreau and his older brother John made a two-week boat-and-hiking trip from Concord, Massachusetts, to the White Mountains of New Hampshire. After John's sudden death in 1842, Thoreau began to prepare a memorial...