The source article defines dropshipping and discusses its modern online-retail context, including early platform-era examples, but names no year or decade for when the practice began or when the term itself entered use.
What would resolve this A retail-history source giving a specific year for the first documented drop-shipping arrangement, or explicitly stating that mail-order drop-shipping has no single citable origin because it grew gradually out of ordinary wholesale distribution.
OpenBusiness HistoryWikipedia, Drop Shipping