Mark Twain wrote something called The Literary Offences of James Fennimore Cooper. I've never read it, though.
I had to read Cooper in high school and it was practically insufferable.
As I understand it, Twain had two major gripes with Cooper. One was his literary style, which is definitely pre-modern. The other was that Cooper clearly felt that individual American Indians were capable of high moral qualities. As an American who lived near the frontier, Twain did not consider Amerindians to be truly human.