From 1837 to 1861 Thoreau kept a Journal that began as a conventional record of ideas, grew into a writer's notebook, and eventually became the principal imaginative work of his career. The source of much of his published writing, the Journal is also a record of both his interior life and his monumental studies of the natural history of his native Concord, Massachusetts. In contrast to earlier editions, the Princeton Edition reproduces the Journal in its original and complete form, in a reading text that is free of editorial interpolations but keyed to a comprehensive scholarly apparatus. Despite activities as time-consuming and varied as surveying for the town of Concord and helping a fugitive slave escape to Canada, Thoreau wrote nearly eight hundred manuscript pages in his Journal during the eight months covered by this volume. Confirmed in his vocation as a natural historian, he began to compile the richly detailed records of Concord's woods, fields, and streams that would occupy him for the rest of his life, and he consciously shaped the Journal to reflect his new aims as a writer. He also began major revisions of his Walden that would lead to its publication in 1854.