The Kingdom of Prussia, in existence from the early 17th century until the early 20th century, was a European kingdom originating from the nation of Germany. In the New World, the Germans ruled territories in South America in the 1500s such as Venezuela.
The Germans in Age of Empires III start off with fewer, but faster gathering villagers than other civilizations. They receive free Uhlans with every Home City Shipment though they require more experience points per shipment (the opposite of the Spanish). Their early age economy can easily be bolstered with their Settler Wagons which essentially do the work at the rate of two villagers. Although they are only available through the Home City in the beginning, they can later be trained at the mill with the Germantown Farmers card. This card also requires a level 25 Home City.
Because the Germans always have Uhlans, they have strong cavalry and their late-developing army is diverse. The units you could have in a strong army of are; Skirmishers, Uhlans, Doppelsoldners, or a few powerful War Wagons. German cavalry is one of the strongest in the game, especially the War Wagon while the Uhlans have a mediocre HP but a devastating attack. Their cavalry can further be strengthened since they have over five shipments that can aid their combat ability. The Germans can also obtain free mercenary shipments long before any other civilization can.
They appear in the Act I: Fire (The War Chiefs) as the Hessians, from Hesse and allied with the British. The reason for this is because the British used several Hessian mercenaries in the War of Independence.
Palatine Settlement - Houses now provide 30 population space (often included in many decks to compensate for the Germans rapid population space usage and for avid rushers.)
TEAM Teutonic Town Center - TEAM +30% Town Center hitpoints, TEAM +50% Town Center attack.