The fort was designed by the French military engineer Col. Louis Cambray-Digny. The first sections constructed were the corners, or bastions, which served as strong points against attack. A firing step, or elevated platform, was built into each, where perhaps six to eight riflemen could look over the landscape to defend the fort. The drawing shows the eight postholes that supported the step and a fire-baked hearth where soldiers kept warm in the nook beneath.