The novel spans a couple of years and a few thousand miles, beginning in Kansas and ending in Washington Territory. Aiden and his little sister Maddy are orphaned and starving on their family's farm in Kansas, where drought has ruined any chance of farming any longer. When they are given an opportunity to join a wagon train west and work for a logging company there, they are willing to agree to whatever terms are necessary to pay their way across the frontier.
Although people who haven't read the book or seen the movie probably won't think "historical fiction" when they think of this book, Water for Elephants is actually a very fine example of the genre. It's a well-researched story about a vet school dropout who joins the circus during the Great Depression after the deaths of his parents. Although the focus of the novel is his relationship with one of the performers, and the conflicts with her husband and the owner of the circus (two different people, although in the movie they were combined into one character), history plays a large part in the setting and story. In fact, in the afterword, the author talks about her research on the history of circuses and the way elephants were treated, which she drew on to write the novel.