A smokehouse and its twin, a small square building whose original purpose and location are still unknown, stand at opposite ends of Sully house. In the smokehouse, meats were hung overhead to cure from wooden pegs which are still visible.

    Two feet thick at the base and 25 feet tall on its highest side, the dairy may have been the only quarried stone building on the property. Probably constructed with some slave labor, its inner and outer walls were insulated with a mixture of earth and straw to insure relatively cool temperatures for the storage of milk, cheese and butter. During the summer months, eggs, fruits and vegetables would have been kept there. The second floor "elegant apartment," as Lee noted in a description of his dairy, may have served as living quarters for an overseer, or domestic workers, but there are no references to actual tenants during the period of the Lee residency.

    Additional structures supporting farm activities and the quarters housing the slave community would have been an integral part of the Sully landscape. In 1794, Stephen Collins described slave "huts... as different from such as I have sen for that purpose in the lower part of Virginia..." Based on available data, archaeologists have determined that one slave quarter was located approximately 300 yards from the main house adjacent to the farm building area and near the south lane bridge which crossed Cain's Branch.