All the larger buildings here were rebuilt or repaired after the US Civil War. In many cases the original bricks were used. It makes sense to use brick, even in the 1700’s. This land is marshes with clay, has termites, and fire was always a danger. There were a few rice plantations that also had a thriving business making bricks.
The pond in the foreground above had been for Water Buffalo. During the rice planting era Water Buffalo were imported and used in the rice fields like all other rice growers around the world. During the federal army’s marsh past Charleston the Buffalo were confiscated. Several actually turned up in the NYC Central Park zoo.