Why is it necessary to understand America and its history as a nation to understand The Adventures of Huckleberry Finn. Can the novel be enjoyed...

Some of the deepest themes of the book, those of slavery
and the inability of people to avoid judging and categorizing others are certainly
understandible without a deep history of the American nation.  What changes, if the book
is read with a knowledge of these things, are some of the more specific aspects of both
Jim's quest for freedom and the interactions between and among the various
characters.

There are so many interesting questions that
can be asked that become more interesting still with an understanding of the history of
the country, and the forces changing things in that moment.  The country was about to be
swept by the idea of compulsory education, and Huck is in some ways a model of what can
be accomplished (in terms of educating oneself) with hard work, curiosity and an
inclination to get into stick situations.  This can become even more nuanced with an
understanding of Twain's views on education.

These kinds of
things go throughout the book.  I can echo the previous post in that the understanding
isn't necessary to enjoy the story, but it can certainly add some interesting levels to
discussions of the book, the characters, and Twain's own attitudes that are evident in
his writing.