His book recounted a seven - day boat trip on the rivers with his brother John , who had since died .
Henry David Thoreau wrote his first book , A Week on the Concord and Merrimack Rivers , in 1849 while living at nearby Walden Pond .
Henry David Thoreau 's book recounted a seven - day boat trip on the rivers with his brother John , who had since died .
Henry David Thoreau wrote his first book , A Week on the Concord and Merrimack Rivers , in 1849 while living at nearby Walden Pond .