I just read this part so Ill contribute it:

        "All right, then, I'll go to hell" - and tore it up. (the letter
he wrote to Miss Watson illustrating where Jim was)

        It was awful thoughts and awful words, but they was said. And I
let them stay said; and never thought no more about reforming. I shoved
the whole thing out of my head, and said I would take up wickedness
awhich was in my line, being brung up to it, and the other warn't. And
for a starter I would go to work and steal Jum out of slavery again; and
if I could think up anything worse, I would do that too; because as long
as I was in, and in for good, I might as well go the whole hog.

This is on page 210 of the Signet Classic edition.

Micah