The Fort is a military building in American Conquest and American Conquest: Fight Back. It usually is the first building you can build as a European faction. It is needed to produce and upgrade 17th-century infantry units, like Pikemen, Musketeers, Arquebusiers and the 17th-century officer, drummer and standard-bearer.
Though to produce all available units at the Fort, Build arsenal (1000 Food) may need to be researched first.
Russia does not have access to Harquebusiers, 17th-century standard-bearers, and drummers and therefore cannot train them at the Fort.
Like the Fortress, it will shoot with cannons on enemies once units are deployed inside it. This can be risky at times, since it can also hit and set ablaze your own or allied buildings if they are in the way.