"To the Person Sitting in Darkness" was published 100 years ago this
month and I've just set up a page at my Twain site that reviews the first
week of the debate about the essay:

A Week in Review: "To the Person Sitting in Darkness" Debated
http://marktwain.about.com/library/texts/bl_tpsd_wk1.htm

It links to the essay, Howells's "Mark Twain: An Inquiry," which was
published along with it, and about 10 editorials and a political cartoon
that
were published during the first week.  Another dozen or so editorials and
five cartoons published later are also available at the site.  I thought
some
of you might enjoy reading through them during the essay's centennial.

Jim Zwick