"They have a queer way of building one thing after another, the great point being to have a separate shed or out-house for every purpose?You will find a carpenter's shop, tool room, coach-shed, pig-house, stable, kitchen, two or three barns, and half a dozen negro huts, besides the main house."
—Theodore Lyman, Union officer stationed in Northern Virginia
The stones on the ground in front of you are the foundation of one or several attached outbuildings. As with most buildings of the 18th and 19th century America, it was probably built entirely of wood above the stone foundation and not meant to last. It eventually fell into disuse (other outbuildings burned) and rotted away or was salvaged for materials.
The Machen family mentioned many outbuildings in their letters and farm logs. The dairy, ice house, smoke house, barn, stable, cow house and pig house were all specifically named. However, as Mr. Lyman says above, there were usually many and diverse outbuildings for almost every conceivable use on 19th century Virginia farms. Although we don't know exactly what this building(s) was used for at any one time, we have some clues.
A life-long resident of this area, Mr. James Brooks, indicated that slave quarters stood in this general location at one time. The Brown family who owned this farm from the 1760s until 1843 had as many as 20 slaves.
There certainly were slave quarters somewhere on the property. The Machen family is only known to have owned one slave, Sally, who probably lived in the farmhouse. However, they hired slaves from other local farmers and had to house them. This location behind the main farmhouse is a typical location for slave quarters. If all or part of this building was used for slave quarters at some time, that is only part of the story.
Archaeology conducted at this site in the 1970s uncovered tools, horse equipment and domestic articles (tableware and dishes). This tells us that the building was used as a tool shed, a tack house (to store horse harness) and as a human dwelling. It's possible that these varied uses took place at different times or in different rooms at the same time. As with many outbuildings, it served whatever need the current residents had.