Question: Who was the great-grandfather of the author of the "Adventures of Huckleberry Finn" and went to Kentucky with the first State Representative of Casey County?

Context paragraphs:
Tom Sawyer &amp; Huckleberry Finn: 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.

Adventures of Huckleberry 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 no Bōken: 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".

Mark Twain: Samuel Langhorne Clemens (November 30, 1835 – April 21, 1910), better known by his pen name Mark Twain, was an American writer, humorist, entrepreneur, publisher, and lecturer.  Among his novels are "The Adventures of Tom Sawyer" (1876) and its sequel, the "Adventures of Huckleberry Finn" (1885), the latter often called "The Great American Novel".

Casey County, Kentucky: Casey County is a county located in the U.S. Commonwealth of Kentucky.  As of the 2010 census, the population was 15,955.  Its county seat is Liberty.  The county was formed in 1806 from the western part of Lincoln County and named for Colonel William Casey, a pioneer settler who moved his family to Kentucky in 1779.  It is the only Kentucky county entirely in the Knobs region.  Casey County is home to annual Casey County Apple Festival, and is a prohibition or dry county.  It is considered part of the Appalachian region of Kentucky.

Huckleberry Finn (1920 film): 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".

Huckleberry Finn and His Friends: 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.

Christopher Riffe: Christopher Riffe (1764-1850) accompanied Col. William Casey (great-grandfather of Mark Twain) to Kentucky in 1784.  Riffe lived at Bryan's Station, Boonesborough, Logan's Station and Carpenter's Station.  He bought 800 acre of land from the grandfather of Abraham Lincoln.  Riffe became the first white settler of Casey County in 1793.  He was the first State Representative from Casey County, served seven terms.  He fought in the Battle of the Thames (in which Tecumseh was killed) in the Kentucky Sixth Regiment.  He was Lieutenant-General of the Kentucky State Militia.

Huckleberry Finn (1931 film): 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.

Tom Sawyer, Detective: 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.

Supporting paragraphs: Christopher Riffe Mark Twain
Answer: Col. William Casey