When you click your Town Centre (the same building from where you train your villagers), you have a button which can train a Fort wagon for 500f, 500w and 500c. There is no Fort Wagon shipment available from the home city as your civ is Haudenosaunee. hahahah ... you are a genius and I'm so stupid ...

you are correct and that's the problem,
the fort card is not available on TC nor on the technology tree

Hi everyone, I'm playing the story mode fire and shadow in scenario Saratoga.
The objective is to build three fortress and I can't get the fortress card in my deck at all. though I have 2 cards available, but the technology tree doesn't have the fortress card. can you guys help me please. thanks