I bring this up because I just got my copy of a new book by Kent Carroll and Jodee Blanco, I, John Kennedy Toole, that is a work of fiction but sticks to the facts about the writer. It turns out, for example, that, notwithstanding the tale of repeated rejection Toole's mother promoted, Simon & Schuster was seriously interested in publishing A Confederacy of Dunces. But Toole's editor, Robert Gottlieb (who had edited Catch-22), wanted him to trim the story and sharpen the plot, which Toole attempted to do. Years went by before Gottlieb finally rejected the novel, saying "It really isn't about anything." (Shades of "Seinfeld!")
On a related (and belated) note: Back in April, our friend Octavio Roca kindly shared with me a delightful essay in LitHub titled "Finding Permission to Fail in A Confederacy of Dunces." I encourage any of you who share my enthusiasm for the novel to check that out.