The four buildings creating a quadrangle on the north end of the Historic Garrison originally housed enlisted soldiers. After the demolition of the original headquarters, Building 8, the structure closest to the river, served as temporary post headquarters. The quadrangle buildings currently serve as quarters for mid-ranking officers and NCOs.
The Sally Port on the east side of the quadrangle is the last remaining portion of the original post wall, which surrounded the garrison. About 12 feet high and a couple feet thick, it was not built for a siege or artillery attack, but rather potential civil unrest or a slave revolt. American authorities generally had good relations with the native Creole population, but the authorities did not completely trust them at this point. As elsewhere in the Antebellum South, the fears of a slave uprising were always present.
The remaining towers fell into disuse but were converted into unique residential space during the WPA construction and renovations of the 1930s. They remain in use as temporary VIP quarters to this day.