They started clearing the land in 1847 and with slave labor and a civilian workforce consisting of blacksmiths, bricklayers, stonecutters, carpenters, and other skilled laborers, established a tabby foundation in 1850, and over the following 6 years, 2 and a half million bricks were laid constructing two curtain walls, the north bastion, the guardroom, the prison, and the carpentry shops. Two southern brickyards in Savannah and Saint Marys provided brown brick from 1847 to 1860. Three northern yards in New York, Maine, and Pennsylvania provided red bricks from 1862 to 1867. the total number of bricks is approximately 5 and a half million. New Hampshire granite was used in the staircases, windows, door sills, lentils, and cannon platforms. Pennsylvania brown sandstone supported door hinges. The Core of Engineers contracted with Reid's Sawmill here on Amelia Island for the purchase of the timber. The sawmill provided oak, pine, and cypress for vaulted arch ceilings, doors, windows, and roof trusses. A new building material for the time was cast iron. You will see that from behind the barracks later in the tour.