In HF, Twain uses Huck as the narrator. The use of the 'N' word is
part of Huck's background, vocabulary, and education or lack thereof.
It is part of his character. I think a more accurate indication of
Twain's feel for the word (at least in the 1870s or so)can be seen in
_Tom Sawyer_. Twain, as the narrator, never uses it, referring to the
slave children of St. Petersburg as "Negro boys and girls." The
kindly Welshman, who appears to be better educated than most in town,
uses the term "my Negro men." Injun Joe, Huck Finn, and Tom are the
only characters who use the "n" word. It appears that an argument
could be made that Twain was aware of the derogatory nature of the
term and was using it to create characters of low education or social
standing.

John Evans