Concord, Mass. Thoreau writes in his journal:

Thoreau also writes to Jonathan Buffum (The Writings of Henry D. Thoreau (ucsb.edu); MS, Pierpont Morgan Library, New York, N.Y.).

Lynn, Mass. Charles C. Shackford writes to Thoreau (The Writings of Henry D. Thoreau (ucsb.edu); MS, Special Collections, Concord (Mass.) Free Public Library).