The bulk of the excavation was done 1989-1991, when archaeologists uncovered the remains of the Wing and part of the yard in front of it. They found the original brick floors, stone hearths, wall foundations, and a stone retaining wall, as well as thousands of artifacts from Jefferson's time.

The architectural remains and artifacts showed that the wing was 100 feet long and nearly 23 feet wide, with a covered passageway along its southern face. The evidence also indicated how the wing was used. A narrow L-shaped space, open to the south, separated the house from the first full room. This first room was unheated, and may have served as storage. Next came a kitchen, a cook's room (that may have doubled as a laundry), and a smokehouse.

Artifacts retrieved from the excavation include: a fork with a bone handle, dyed green in imitation of jade, Chinese porcelain tea and coffee wares, and English transfer-printed plates.

The artifacts confirm what granddaughter Ellen said about Poplar Forest: "It was furnished in the simplest manner, but had a very tasty air; there was nothing common or second rate about any part of the establishment though there was no appearance of expense." Jefferson incorporated many features in the wing considered modern for the time.

Archaeological evidence suggests that some time in the 1840s, the wing no longer stood.  The family who owned the property at the time tore down the two rooms closest to the house, and refashioned the remaining two rooms into a freestanding kitchen and a smaller smokehouse.  In the 20th century, the two buildings were reconnected by a narrow room that served as a bathroom.  The entire complex was converted to a guesthouse.