Although the word is not used, Twain's zany novel of title-frenzy and mad-scientist capitalistic schemes The American Claimant (sequel to The Gilded Age) describes the intent by the megalomaniac Mulberry Sellers to "materialize" dead people for use as cheap labor. He intends to contract these would-be minions of his out as policemen and soldiers and such, thus saving city and national governments big money while reaping a giant profits for himself.
Is this 1892 novel the first to include "zombies" among its characters?
Actually, these "zombies" never really materialize - they remain figments of Mulberry's overfertile imagination; yet still, as far as the concept goes, is this the "advent of the zombies"?
If so, Twain was not only ahead of his time, again, but a case could be made that he foresaw the inroads that robots would make into the labor market (if you stretch or conflate "zombies" to "robots").