Dear William Dean Howells Society:
I am writing about John Greenleaf Whittier’s 70th birthday party, at which Mr. Howells was the toastmaster, and at which Samuel Clemens gave his controversial speech.
In Mr. Howells’ account of that speech, he says that the silence “…deepened from moment to moment, and was broken only by the hysterical and blood-curdling laughter of a single guest, whose name shall not be handed down to infamy.”
My question is, is it known, now, who that guest was? I’m wondering if it showed up in any of his correspondence or personal notes.
Sincerely,
Stephen Sakellarios
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W. D. Howells Society 
Would it have been Howells himself?
All best,
Owen Clayton
[reposted from howells-l]
It was Longfellow! See here.
http://twain.lib.virginia.edu/onstage/whitnews.html
Scroll down untill you get to the description of the “eccentric” speech and you will see the record of Longfellow’s behavior.
Rosslyn Elliott
From Tom Wortham:
I’m in the process of reorganizing my library, and so I can’t find Henry Nash Smith’s MT: The Development of a Writer (1962), but I seem to recall that having noticed that the Boston newspaper report indicated [laughter] at several places during its account of the speech, Smith argued that perhaps Howells’ own discomfort that evening caused him to misremember the audience’s reaction to the talk. Tom Wortham
Francis James Child, the collector of English historical ballads and folk balladry, is suposed to have been the person who laughed at the back of the audience, probably becuase his work in folk resources allowed him to “get” the humor of what Twain was doing in pretty much the spirit Twain intended. Child, I believe, continued to think that the audience was unreasonably cool to the speech, long afterwords. I cannot supply the source of this information, though, since I noticed it in passing. Dave Sloane
It was Mathew Franklin Whittier, younger brother of the birthday boy, John Greenleaf Whittier. He had ghost-written the story for Clemens, probably setting it in New England, and Clemens had reworked it so as to set it in California. It was Mathew’s practical joke and birthday present to his brother. I have quite a bit of background evidence–e-mail me if you’re interested.
ssake-at-goldthread-dot-com
Stephen Sakellarios