This is not related to Twain's reading of Don Quixote but might be of
interest as a later indirect influence of the novel. An interesting chain of
inspiration began with the idea that Twain might become "a new
Cervantes" who could end militarism and war with his satire. The first
three paragraphs are from

Mutual Inspiration: Twain, Crosby, and Beard on American Imperialism
http://www.boondocksnet.com/ai/twain/twain_crosby_beard.html

Mark Twain's early anti-imperialist statements led to a little-known
episode of mutual inspiration involving Twain, Anti-Imperialist League of
New York President Ernest Crosby, and Dan Beard, illustrator of A
Connecticut Yankee in King Arthur's Court. On January 16, 1901, three
days after Twain joined the Anti-Imperialist League of New York, Ernest
Crosby gave a speech on "The Absurdities of Militarism" at a peace
conference held at Tremont Temple in Boston. During the speech, he
noted that Cervantes ended the literature of chivalry with the satire in
Don Quixote and suggested that "a new Cervantes" should arise to
destroy militarism by making it equally laughable.

"There is an opportunity today for a new Cervantes to perform a far
greater exploit than has ever been ascribed to the Spanish author. A
new Don Quixote might, nay, could, make the profession of war
impossible by opening our eyes to the irresistible comicality of it. Mr.
Dooley has done excellent work in this direction. Mark Twain has given
some evidence of his insight into the truth. Will not one of these
gentlemen, or some other genius yet to be discovered, turn his winged
shafts squarely against war and the war-maker?"

After the speech, two officers of the New England Anti-Imperialist
League who were in the audience suggested to Crosby that he write the
book himself. He agreed, and completed Captain Jinks, Hero, before the
end of the year. It was the first of only two anti-imperialist novels
published during the Philippine-American War. Dan Beard illustrated the
novel, and in December of 1901 he asked his friend Mark Twain to
review it.

Crosby's novel and Beard's illustrations are closely related to Twain's
writings of early 1901, with sections on hazing at West Point, the
business of imperialism, and missionary activities in China. In Dan
Beard's illustration "A Blood Brotherhood," a figure representing the
Trusts holds a barrel labeled "For Him Who Sits in Darkness" that is full
of unjust tax bills, government by injunction, whiskey and beer.

Twain's review of the novel was very brief and focused on one chapter
satirizing Frederick Funston's deceitful capture of Filipino General Emilio
Aguinaldo. The novel that was partly inspired by Twain ended up
inspiring Twain. In a private note at the end of the review, Twain added,
"I wrote a short article about Funston last night -- for the May North
American." That was the beginning of "A Defence of General Funston."
Twain had been working on a serious review of a biography of
Aguinaldo. After reading the novel he decided to try his hand at a satire
of Funston and took a section about Aguinaldo's capture from the review
to begin the satire.

Jim Zwick