The most famous mega-sentence in literature comes at the end of the book, not the beginning. Molly Bloom's monologue from "Ulysses" (1922) --36 pages in the thinly margined, micro-fonted 1986 single-volume corrected text (and actually two long sentences, thanks to an often-overlooked period 17 pages in) -- sets an impossibly high standard for the art of the run-on. It breathlessly binds together all that comes before while nearly obliterating it, permanently coloring the reader's memory in one final rush. It feels unstoppable, and then it stops.
The Book-Length Sentence In The Age Of Twitter