Built circa 1767 as the second enlargement of the Mabee homestead, the Brick House contains a cellar with a fireplace and an unfinished garret. Its mixed-use history has made its exact purpose uncertain, with theorized uses including living space, a summer kitchen, storage room, and housing for enslaved Africans. The three-century success of the Mabee farm depended in part on 120 years of forced labor by enslaved Africans. While the main floor was well finished and elegantly decorated for family members, the enslaved were forced to live in the damp basement with few comforts. Over the last century, the building was used for storage and never updated with modern conveniences, leaving it barely altered from its original appearance and preserving the characteristics and construction of late eighteenth century rural houses.