Question: What year was the novel written which the 1931 film Huckleberry Finn was based upon?

Context articles: The Adventures of Huck Finn (1993 film)
Huckleberry Finn (1920 film)
Tom Sawyer &amp; Huckleberry Finn
The Adventures of Huckleberry Finn (1960 film)
Adventures of Huckleberry Finn
Huckleberry Finn and His Friends
Huckleberry no Bōken
Tom Sawyer, Detective
Huckleberry Finn (1931 film)
Tom Sawyer

The Adventures of Huck Finn is a 1993 American adventure film written and directed by Stephen Sommers, distributed by Walt Disney Studios Motion Pictures and Buena Vista Pictures, and starring Elijah Wood, Courtney B. Vance, Jason Robards and Robbie Coltrane; it is based on Mark Twain's novel "Adventures of Huckleberry Finn" and focuses on at least three-fourths of the book.
 The film follows a boy named Huckleberry Finn and an escaped slave named Jim, who travel the Mississippi River together and overcome various obstacles along the way.
Huckleberry Finn is a surviving American silent dramatic rural film from 1920, based on Mark Twain's classic "Adventures of Huckleberry Finn".
 It was produced by Famous Players-Lasky and distributed through Paramount Pictures.
 William Desmond Taylor directed "Huckleberry Finn", as he had the 1917 film version of "Tom Sawyer", using a scenario written by Julia Crawford Ivers, who also had been the writer for "Tom Sawyer".
Tom Sawyer & Huckleberry Finn is a 2014 American comedy-drama/adventure film starring Joel Courtney as Tom Sawyer, Jake T. Austin as Huckleberry Finn, Katherine McNamara as Becky Thatcher, Noah Munck as Ben Rogers, and with Val Kilmer as Mark Twain.
 It is based on Mark Twain's novels "The Adventures of Tom Sawyer" and "Adventures of Huckleberry Finn".
 Directed by Jo Kastner, the film is released by VMI Worldwide.
The Adventures of Huckleberry Finn is a 1960 American film directed by Michael Curtiz.
 Based on the Mark Twain novel of the same name, it was the third sound film version of the story and the second filmed by Metro-Goldwyn-Mayer.
 The film was the first adaptation of "Huckleberry Finn" to be filmed in CinemaScope and Technicolor.
 It starred Eddie Hodges as Huck and former boxer Archie Moore as the runaway slave, Jim.
 Tony Randall also appeared in the film (and received top billing), and Buster Keaton had a bit role in what proved to be his final film for his old studio, Metro-Goldwyn-Mayer.
 Neville Brand portrayed Huck's alcoholic father, Pap Finn.
Adventures of Huckleberry Finn (or, in more recent editions, The Adventures of Huckleberry Finn) is a novel by Mark Twain, first published in the United Kingdom in December 1884 and in the United States in February 1885.
 Commonly named among the Great American Novels, the work is among the first in major American literature to be written throughout in vernacular English, characterized by local color regionalism.
 It is told in the first person by Huckleberry "Huck" Finn, a friend of Tom Sawyer the narrator of two other Twain novels ("Tom Sawyer Abroad" and "Tom Sawyer, Detective").
 It is a direct sequel to "The Adventures of Tom Sawyer".
Huckleberry Finn and His Friends was a 1979 television series documenting the exploits of Huckleberry Finn and Tom Sawyer, based on the novels "The Adventures of Tom Sawyer" and "Adventures of Huckleberry Finn" by American writer Mark Twain.
Huckleberry no Bōken (ハックルベリィの冒険 ) is a 1976 anime series based on the novel "Adventures of Huckleberry Finn" by Mark Twain.
 It is the first of two Huckleberry Finn anime.
 A second Huck Finn television series was made in 1994, "Huckleberry Finn Monogatari".
Tom Sawyer, Detective is an 1896 novel by Mark Twain.
 It is a sequel to "The Adventures of Tom Sawyer" (1876), "Adventures of Huckleberry Finn" (1884), and "Tom Sawyer Abroad" (1894).
 Tom Sawyer attempts to solve a mysterious murder in this burlesque of the immensely popular detective novels of the time.
 Like "Adventures of Huckleberry Finn", the story is told using the first-person narrative voice of Huck Finn.
Huckleberry Finn (1931) is an American Pre-Code comedy film directed by Norman Taurog and starring Jackie Coogan as Tom Sawyer and Junior Durkin as Huckleberry Finn.
 The picture was based upon the novel "The Adventures of Huckleberry Finn" by Mark Twain.
Thomas "Tom" Sawyer is the title character of the Mark Twain novel "The Adventures of Tom Sawyer" (1876).
 He appears in three other novels by Twain: "Adventures of Huckleberry Finn" (1884), "Tom Sawyer Abroad" (1894), and "Tom Sawyer, Detective" (1896).