Nathan Bedford Forrest

The subject of this article: exists in the Forrest Gump novel canon (including Gump & Co.) exists in the Forrest Gump film canon exists in real life (see Wikipedia article: Nathan Bedford Forrest)

General Nathan Bedford Forrest is an ancestor of Forrest Gump (who was named after him), a Civil War general and first Grand Wizard of the Ku Klux Klan, According to the Forrest Gump film, Mrs. Gump named Forrest after this KKK Wizard to remind him that "sometimes we all do things that just don't make no sense." 

Forrest is remembered both as a self-educated, innovative cavalry leader during the war and as a leading southern advocate in the postwar years. He was a pledged delegate from Tennessee to the New York Democratic national convention of the 4th of July 1868. He served as the first Grand Wizard of the Ku Klux Klan.

Later in the novel

Upon hearing Forrest's name, educated tribesman Big Sam correctly guesses "famous Civil War General Nathan Bedford Forrest" as its inspiration.