Chapter 4, brief tell, Huck is progressing with his new life with the Widow and even gets a little school done. One winter morning, he sees footprints, with an imprint of a cross formed by what seems two nails on the left heel only. A symbol he reconizes. After selling all his share of money after his encounter with Engine Joe, to Judge Thatcher for a dollar, he runs to Jim to tell him about the cross, in which he recognizes as his father close by.
I'm not sure if these are answers? BUT I would say the setting explains what's happening and where they are, which give you a better idea on what's happening and lets you imagine, and understand the story more clearly.
