The site that we know refer to as the "Tobacco Barn Quarter," which lies just to the west of the modern Visitor Center, has had many designations over the past 25 years.  A scatter of artifacts just to the north gave the area it's first name in 1987: the Brick Clamp, named because it was suspected that the area was utilized for the production of bricks.  Following that, subsequent documentary research would reveal the account of Dr. George Bagby1:

I lingered a while in the little brick-walled graveyard.  Not a living being was visible.  Everything was profoundly still and sad.  Being told that the house was near at hand, though no sign of it could be seen, I walked onward, passing on the way a broken-down tobacco-house—itself a monument for a crop no longer grown in Orange. 

The site now had a new name: the Tobacco Barn Quarter, a part of the Field Complex that included an overseers house near the original Madison homestead, Mount Pleasant.  When excavations in 2004-2005 unearthed a scatter of rocks consistent with an "armored surface" for a work yard, and a borrow pit full of domestic artifacts that revealed the nearby location of a log cabin home for field laborers.  Although the name didn't change, our interpretation of the site had now shifted away from agricultural activity and more towards the domestic occupation by enslaved field laborers, in essence focusing on "field slave quarters."

With the 2012 excavations, as detailed in Matt Reeves' last post, the suspected log cabin homes were now a threshing barn, even if it was clear that it was also used as a domestic home for some part of its lifetime.

Brick Clamp.  Tobacco Barn.  Field Slave Quarters.  Threshing Barn.

And, now, time to go "there and back again..."

One piece of evidence that we have not been able to make fit, however, were the 16x16' burned trenches.  In his previous post Matt had this to say of the trenches:

These structures were outlined by a foot-wide trench containing a burnt clay bottom with ash.  Evidence suggests the burnt trench was designed to receive the bottom-most sill for a log structure.  In pondering the reason for a burnt trench for the bottom log, there is potential the brick-like surface drew water away from the log to prevent rot. The ash would have also helped in this process by deterring insect infestations.

There is a precedent for this at Montpelier.  The post holes for the fence line of the Front Yard were charred at the base to help moderate insect infestation and rot.  It would make sense if the structure was designed to be long-lived, but the homes of laborers—as Matt noted—were often considered expendable, so why this extra effort when it was absent in the log cabin near the mansion?

The seed of an answer would come from an impromptu discussion on the relative meanings of "planter" and "farmer" between the archaeology and curatorial departments.  A newly-identified document revealed that even while wheat was the principle cash crop, tobacco was still being grown at Montpelier until the property was sold in 1844.  Could that be the answer to those trenches?

Additional historic research into the structural forms of tobacco barns (or sheds) and the traditions of tobacco growing would provide some interesting tid-bits.  The first piece of evidence was that traditional tobacco barns averaged 17x17 ft.2

Log barns are essentially the pioneer type.  Old style barns were merely cribs of logs roofed over… Ordinary barns are generally built of hewn logs, with interstices “pointed up” with lime mortar or mud.  An average size is 17 feet square and 17 feet high, with hipped roof.  For supporting sticks or poles of tobacco a barn of this size would have four sets, or rooms, of tier poles, four high.  The lowest would be 8 or 9 feet above grade.

So, the approximately 16x16-ft trenches would fit within that structure, but would you really want fires next to wooden walls?  The answer to that particularly question would come from a publication by the Missouri State Board of Agriculture3

I have a small trench in the barn on each of the four sides, as near to the side of the barn as I can safely.

I have no trench through the middle—none is needed.  When I commence curing I make very small fires all round, and gradually increase them as fast as I can without “coddling” the leaves, i.e., scaling or cooking it, which turns it black and renders it nearly worthless.

While Missouri might be a little distant, Virginian tobacco grower Robert Stevens (known as "Buster") noted that4

Prior to 1870 smoke from the fire went around inside the barn in ditches and came out between the fireboxes.  These ditches were covered with flat rock or metal later on when metal was available.

The archaeological literature is remarkably silent on the subject, most likely because these structures are commonly located in fields that would have been subsequently plowed over, thus destroying the evidence.  The Tobacco Barn Quarter might therefore represent a completely unique archaeological find, and while further historical research and consultation with experts in barns and similar structures performed, the evidence is remarkably compelling.

What does the evidence suggest?  Originally three tobacco sheds, possibly with a single roof, were built in the early-19th century next to the old patent road and in sight of the overseer's house.  These tobacco sheds were sufficient for the fire-curing of 28 acres of tobacco, a process that took about 5 days in August.  For the rest of the year?  It's possible that it was used as a home for enslaved field laborers, perhaps even the skilled individuals that oversaw the delicate fire-curing process.  At some point, however, the decision was made to turn the three sheds into a wheat-threshing barn, similar to the traditional three-bay or "English" threshing barn.  

At this point we move into speculation based upon the historical documentation.  In the previous post Matt highlighted the court case between Henry Moncure and John Payne Todd with regards to the alleged theft of a threshing machine, an event which caused some damage to both the machine and the structure within which it was built.  While we have no definitive evidence that the structure identified in 2012 was the same structure as the one from the court case, it does fit the archaeological evidence and, well, it makes a great story.  Thus, we are given to understanding that after the structures were damaged during John Payne Todd's shenanigans, the tobacco barn turned wheat-threshing barn would molder for three decades until Dr. Bagby walked by and noted the run-down appearance of the tobacco barn, unaware of its history as a threshing barn and more familiar with its appearance as a tobacco barn. 

Citations

​1 Bagby, Dr. George W.  1872.  The Home of Madison in 1871.  Lippincott's Magazine, Volume 9: 473-477.

2 Hoagland, I.G.  1910.   The Tobacco Industry: An Exposition of the Process of Growing and Curing Tobacco - The Fire Hazards of Tobacco Warehouse and Drying Machines.  The Weekly Underwriter: An Insurance Newspaper 83, 8-24.

3 Missouri State Board of Agriculture.  1867.  Second Annual Report of the Missouri State Board of Agriculture with an Abstract from the Proceedings of the Country Agricultural Societies to the General Assembly of Missouri, for the Year 1866.  Jefferson City, Emory S Foster, Public Printer.

4 Stevens, R.  1997.  Tobacco in Virginia.  Personal account of a tobacco grower.  Halifax County, Virginia.  [http://www.oldhalifax.com/county/TobaccoHistory.htm]

Mark A. Trickett