Chapter 43: Huck includes this chapter to fill in the reader on a few details. Tom, he says, had planned to escape with Jim on the raft, so that all three of them could have more adventures. After they reached the mouth of the Mississippi, however, he was going to tell Jim that he was free, and then all three of them would take a steamship up the Mississippi back home.
Here also, Jim tells Huck that the dead man in the houseboat was actually his father, so he doesn't have to worry about his pap bothering him anymore, and he can now take his six thousand dollars from Judge Thatcher.
Thus, it's a very happy ending for everyone.