You're right that there's not much compared to other Twain books, but
there's enough to keep you out of
trouble for a while. Read Bryant French's _Mark Twain and the Gilded
Age: The Book that Named an Era_ (Dallas: SMU Press, 1963), and my
afterword to the Oxford Mark Twain's edition of _The Gilded Age_ for a
start.
Gregg Camfield