Browsing Google Books (searching, originally, for old reviews of Bertha Runkle's work, I think?), I stumbled upon a volume from 1901: A House Party: An Account of the Stories Told at a Gathering of Famous American Authors.
I haven't read the book entire, but the premise is intriguing -- invite a number of authors to a party, require them to submit a piece of fiction before the party, redact their names, then distribute the "anonymous" pieces to guests and have them try to guess who wrote what. Now, if only I were friends with people like Sarah Orne Jewett: what a party it would be.