We're going to be honest: this book doesn't quite fit the rags to riches plot. It's more like rags to riches to burned-down house. But we'll take a look anyway, and see how it goes.
When his family moves to a plantation in Tidewater Virginia, Sutpen witnesses the race and class divisions in the real world. It's no longer about being strongest, it's about being rich and white. His poor treatment by a black butler prompts his "design."
Acting on information he learned during his brief education at the plantation, Sutpen leaves his family behind and goes to the West Indies. There he makes his fortune, quells a slave rebellion, and marries the plantation owner's daughter. They have a son. Things are looking up.
Sutpen can't leave Haiti and his family fast enough. He arranges to have his wife and son taken care of and leaves to start over again in Jefferson, Mississippi. Having a black wife and son is not part of his plan.
Sutpen sets himself up like a king, with the estate, the wife, and the kids – the whole nine yards (or hundred square miles, actually). There's only one problem: that darn son from the first marriage is back and wants to (a) be acknowledged and (b) marry Sutpen's daughter (his own half-sister). Charles Bon is a serious wrinkle in Sutpen's design. Plus, Sutpen's other son, Henry, is taking his brother's side!
Faulkner just cannot give his characters a break. Sure, Sutpen gets really rich and he gets the son he always wanted, but then the whole "past" thing catches up with him. He ends up being killed by one of his own farmhands, and later his own daughter burns down the house. So yeah, like we said, rags to riches, maybe, but then back to rags (or, should we say ashes?).