These notes identify real people, places, books, and events that Mark Twain drew upon for Adventures of Huckleberry Finn. They document historical, literary, and cultural allusions, parallels, analogues, or influences, both in the text and in E. W. Kemble’s illustrations. They identify important moments in the seven-year course of composition and in the process of revision and first publication: when Mark Twain wrote or revised parts of the text, when he stopped or resumed work on them, how he struggled with or commented on them. References to the manuscript may distinguish between its newly discovered first half (MS1) and its long familiar second half (MS2), now both in the Buffalo and Erie County Public Library. References to the typed copies of MS1 and MS2 which Mark Twain had made are to the documents which served as Kemble’s and the first edition printer’s copy, but the typescripts themselves are not known to survive. What they probably contained and how Mark Twain revised them are matters inferred from the manuscript, the first edition set from the typescripts, and other evidence. For the history of composition, revision, publication, and reception, see the introduction. References to the text are keyed to this volume by page and line: 3.10 means page 3, line 10. Chapter titles and picture captions are not included in the line count, but when they are referred to, the word title or caption is substituted for the line number: 3 caption means the caption on page 3. Frequently cited books have been assigned an abbreviation, always italicized, which is followed by a page (or volume and page) number: “MTBus, 21” or “MTL , 1:456–57.” But most works are cited by the author’s last name, followed by page number, unless there is only one page: “Abbott, 16–17” or simply “Pease.” When two or more works by the same author are cited, the year of publication differentiates them: “Budd 1985, 1” or “Budd 1962, 34–76.” For works likely to be consulted in any of various editions, citations give chapter numbers (or book, canto, or act numbers) rather than page numbers. Quotations of Mark Twain’s published work are from critically edited texts produced by the Mark Twain Project or from the first printings, as necessary. Quotations from original documents follow their wording and punctuation exactly, even when a published form is also cited and may differ slightly from the original. Repositories of unique documents are identified by the standard Library of Congress abbreviation. [begin page 374] Documents owned by individuals are cited by the owner’s last name. All abbreviations and names used as citations are defined in References, pp. 1121–64.