Concord Free Public Library
The Thoreau Surveys at the Concord Free Public Library. The CFPL is a treasure whose archives are bulging with sources on all the major Concord transcendentalists, including Ralph Waldo Emerson and the Alcott family. They also hold over one-hundred-and-fifity of Thoreau's original, hand drawn maps--including his famous map of Walden Pond. These maps have been digitized and can be found here.