The blockhouses served as lookouts, as the headquarters of General Thomas S. Jesup, and as protection for the troops in the event of an Indian attack. Two blockhouses were constructed on opposite corners of the stockade, twenty feet square with four feet of overhang on the second level. They were built of pine logs plentiful in the area and chinked with a mixture of sand and lime. Each blockhouse protected two walls of the stockade. If an enemy breached a wall, soldiers could move into the blockhouses and continue the fight using the small gun ports on all four sides of the building.