Mark Twain's 1892 novel The American Claimant was written very soon after the Wounded Knee Massacre (1890), which was basically revenge for the 1876 Battle of Greasy Grass ("Little Big Horn"). This unprovoked and wanton slaughter was seemingly the final nail in the coffin of Indian resistance to Euro-American territorial incursion and cultural forced assimilation.
Although "anti-Indian" for the first decades of his life, it seems Twain at the end re-thought his position on them.
Could it be that the titled English heir in The American Claimant (Berkely Rossmore, who even dressed up as a cowboy and took the name Howard Tracy to remain incognito) was meant to represent wealthy Euro-Americans, whereas the uncouth and eccentric American (Mulberry Sellers) was a symbol of the "Indians"?
Note that the character Washington Hawkins, a confederate of Sellers', was from Cherokee Strip (land taken from the Cherokees in the "Oklahoma Land Rush" of 1889).
Also, to quote from the book where the Earl of Rossmore speaks of the rights of the American Claimant: "...morally the American tramp is rightful earl of Rossmore; legally he has no more right than his dog."
Even L. Frank Baum (author of The Wizard of Oz) admitted that the way the Indians were treated was wrong, although he still called for their utter destruction.
BTW, although I love "Tom Sawyer" and "Huck Finn" as much as (and probably more than) the next guy, The American Claimant may be my favorite novel from this, my favorite author. It is at least as topical as anything else he's written, too, and is replete with zombies, robots, mass-produced monstrosities, etc. etc. It could make a great movie. Are you listening, Hollywood? Netflix? Amazon?