Released in 2019, version 1.35 was a landmark update for the game. Key features included:
: Ability to manage your fleet and drivers via the map. The "21 DLCs" Breakdown American Truck Simulator -v1.35.1.3s 21 DLCs...
Note: Some bundles count state DLCs along with smaller add-ons to reach 21 items. Released in 2019, version 1
This is where the bulk of the "21" count comes from. These DLCs add distinct visual gameplay mechanics: Released in 2019