[dredmorbius]

Specifically, works published from roughly 1830 through the first quarter or half of the 20th century, driven by falling publication costs and rising literacy. Charles Dickens on particular developed the model, with The Pickwick Papers, published in 1836. Another notable work, the Sherlock Holmes series debuted in 1887 ("A Study in Scarlet").

Earlier novels (relatively few in number) tended to appear as their own works in whole form, so far as I'm aware. Though many may have been adaptations of other works --- sagas or legends (e.g., the Faust legend), plays, and other forms.

<https://en.wikipedia.org/wiki/Serial_(literature)>