How is the afterword in Bud, not Buddy connected to the rest of the book?

The afterword of this story is the author's explanation of how Bud's story is an example of historical fiction. Curtis says that Bud and the events of his life are completely fabricated; however, the afterword explains that the novel's characters and Bud's story are based on real people and real events. For example, Curtis's grandfathers are the base models for the characters of Lefty Lewis and Herman E. Calloway. Lewis was an actual "redcap" who worked at the railway stations. Curtis didn't invent that character or that job—they were real, and that allows Curtis to position Bud in and around real historical events and happenings. The afterword is an important piece to this book because it lets readers know that Bud's story, while fictional, is quite a realistic showing of the zeitgeist of that era.