The United States of America, simply known as the United States (U.S.), is a civilization introduced in the first expansion content to Age of Empires III: Definitive Edition. It can be unlocked for free by completing a limited-time challenge based on the (present-day) fifty states of the U.S., or purchased on Steam or the Microsoft Store.
General: Instead of an Explorer like European civilisations, the United States has the General. The General can build Forts and plant Inspiring Flags which makes nearby military units and buildings inflict more damage and are also trained/constructed faster.
Minuteman: United States Minutemen can be recruited from Town Centers and Outposts repeatedly over several minutes. They only lose up to half of their hitpoints, allowing the player to also use them to attack the enemy. With a certain card from the Home City, they can be upgraded into United States Marines, which are stronger.
Cowboy: The Cowboy, which can be trained at the Saloon, is an upgrade to the Comanchero and has a charged ability called Bull’s Eye.
Owlhoot: The Owlhoot, which can be trained at the Saloon, is an upgrade to the Renegado and has a charged ability called Buckshot
Gunslinger: The Gunslinger, which can be trained at the Saloon, is an upgrade to the Pistolero and has a charged ability called Quickdraw
Sloop: A ship that is good at exploring and fishing which has a Broadside charged ability. It replaces the Caravel.
Steamer: The Steamer is a steam-powered ship that can fish, train soldiers, and build Docks at nearby coasts. It can also gain a speed boost of 40% with an ability, Full Steam, for 8 seconds. It replaces the Galleon.
Ironclad: The Ironclad is a ship that is a powerful replacement to the Monitor.
Quaker Gun: The Quaker Gun is a decoy unit that deals no damage, but can appear as any common artillery unit.
Meeting House: The Meeting House is a unique Church that trains Surgeons instead of Priests. The United States can train more Surgeons than other civilisations. It also has three unique improvements.
Saloon: The Saloon trains three unique Wild West units, along with three Outlaw units specific to the map.
State Capitol: The State Capitol replaces the Capitol and is available from the Fortress Age. It can train Wagons that become Buildings and also contains unique United States upgrades along with common Capitol upgrades.
The architecture style of the United States post Exploration Age is mainly timber framing. This is historically inaccurate as this style was used predominantly in Europe while British colonies in North America and subsequently the early United States used Georgian architecture instead.