Confirmed Tobacco Facts
The official Resources table lists Tobacco under upkeep resources with no production building and zero listed production. That is a confirmed table entry, not proof that Tobacco can never be obtained by another game system.
Buccaneer Upkeep
The official Pirates table lists 1 Tobacco as upkeep for Buccaneers. Keep that requirement separate from the question of where a first Tobacco supply comes from.
What the Sources Do Not Confirm
The official pages checked do not identify a first Tobacco acquisition event, a fixed map location, a Marketplace delivery route, or a guaranteed trade source. This page deliberately does not invent one.
Safe Verification Path
If you need to verify Tobacco in a live save, record the Marketplace tooltip, the relevant event or trade screen, and the game version. Compare that evidence with a future official Wiki or developer update before turning it into a permanent route guide.