In her foreward to _Is He Dead? A Comedy in Three Acts_ (U of
California Press, 2003), p. xi, Shelley Fisher Fishkin writes that "_Is
He Dead?_ [written in the winter of 1898] marked the end of a period
in Twain's writing life characterized mainly by fitful false starts and
relatively few finished pieces in any genre."

A paper I presented at an MLA conference some years back might be
useful:

Mark Twain on Imperial Washington, 1900-1910
http://www.boondocksnet.com/ai/twain/mla_mtdc.html

It is a reassessment of Twain's so-called "dark years" within the
framework of Frederic Cople Jaher's discussion of cataclysmic writers
in _Doubters and Dissenters: Cataclysmic Thought in America, 1885-
1918_ (London: Free Press of Glencoe, 1964).  Jaher excluded Twain
from his study because

"Those obsessed with the idea of holocaust identified with displaced
groups and associated catastrophe with the elimination of their
compatriots. Twain's estrangement, on the other hand, was personal.
He had never joined abortive crusades or belonged to defeated
movements -- his tragedy was death, illness in the family, and
financial failure. Consequently, his image of the social struggle was
that of a lonely, feeble individual bowing to his fate rather than that of
a defiant force involving society in its own destruction."

I argue that Twain fits the cataclysmic model because

"We now know ... that Twain did join 'abortive crusades' and belong to
'defeated movements.' During his last ten years he campaigned
against Tammany Hall corruption in New York; served as a vice
president of the Anti-Imperialist League; made lobbying trips to
Washington as a vice president of the American Congo Reform
Association; maintained his earlier association, dating back to 1891,
with the American Friends of Russian Freedom; organized benefit
performances of two of his stories for the Children's Theater for
immigrants on the Lower East Side of Manhattan; and lent his name,
at least, to the Washington-based People's Lobby and to numerous
other causes. He also identified with the political movements he
joined, especially with the anti-imperialists."

Besides documenting some of that, the essay looks at how Twain's
activism fit within his deterministic philosophy.

I wonder if anyone has considered the influence Twain's exclusive
contract with Harper & Brothers might have had on his decisions
regarding publication (and the piles of unfinished manuscripts he
accumulated during those years).  In the "Biographical
Consequences" section of my essay on "Mark Twain and Imperialism"
in _A Historical Guide to Mark Twain_, I argue that Harper & Brothers'
rejection of "The War Prayer" and "King Leopold's Soliloquy" in March
and April of 1905, exacerbated by their delay in releasing the latter for
publication by the American Congo Reform Association, led Twain to
stop writing about imperialism for publication.  That was when he
wrote his series of maxims about free speech being confined to the
dead, and just four months after King Leopold's Soliloquy was finally
published he turned his attention to his autobiography, which he
intended for publication after his death.  Although he continued to
give speeches and interviews about imperialism, he withheld later
literary works on the subject that would have had to be channeled
through Harper & Brothers as his exclusive publisher.  To at least
some extent, his decisions not to publish -- and perhaps not to write --
on certain subjects were the product of business constraints rather
than personal disillusionment.

Jim Zwick