Albert Bigelow Paine,
The Boys' Life of Mark Twain — Chapter 30
(1916)
“ The revised proofs of his book were coming now, and he and gentle Livy Langdon read them together. Samuel Clemens realized presently that the girl he had chosen had a delicate literary judgment. She became all at once his editor, a position she held until her death. Her refining influence had much to do with Mark Twain's success, then and later, and the world owes her a debt of gratitude. ”
