According to Harriet Smith, editor of the book, some of the manuscripts of Twain’s autobiography are handwritten by him but most are transcripts of what he said. These were created on typewriters by helpers such as his secretaries and his youngest daughter. There are three versions of much of the autobiography, including the original. There was a copy used to send 25 sections of the book, one at a time, to be published in "North American Review". Then a copy was used for Albert Paine’s 1924 edition of the book. Clemens proofread them all. Into his vocal dictations, he often inserted earlier manuscripts he wrote and also letters, newspaper clippings and other documents.