Age of Empires III: Definitive Edition - United States Civilization

Unintended reveal

While originally intended to be revealed during the Age of Empires Fan Preview event on 10 April 2021, an employee (supposedly accidentally) changed the "Buffalo" codename in the Steam database to the final one along with the final cover art on 2 April 2021 at 18:06:16 UTC, which was noticed by the community as it was caught on the website SteamDB.info. The title was reverted to the codename an hour later, and the cover art was reverted one further hour later.

Unlock event

For a limited time around the release date, owners of the base game could unlock this DLC for free if they completed a set of 50 challenges representing each state of the modern-day United States of America.