The modern Virginia-Tenneseee boundary line was surveyed originally as a border between North Carolina and Virginia. Tennessee officials were not involved in making those surveys; there was no State of Tenneesee until 1796, when is was carved from the western part of North Carolina. Officials from Tennessee officials shaped the border through lawsuits and political compromises, starting in 1802.
The first key decision shaping the modern Virginia-Tennessee border was made in 1665, when King Charles II declared that the Virginia-North Carolina border would run along along the 36° 30' parallel of latitude, rather than the 36° parallel. Surveyors first started to mark that boundary in 1710, and William Byrd II's famous "dividing line" survey of 1732 stretched inland all the way to the Dan River (Peters Creek).
In 1749, when Peter Jefferson and Joshua Fry surveyed west from Peters Creek, they drifted north away from the assigned latitude. The instruments of the day were imperfect, and accounting for the variation of magnetic north required constant refinement as the surveys moved westward. Fry and Jefferson stopped at Steep Rock Creek (now Laurel Creek, a tributary of Holston River, east of modern-day Damascus).
Virginia began creating individual counties in its southwestern corner in 1772, as the population increased. In 1779, thirty years after Fry and Jefferson had stopped at Steep Rock Creek, Virginia and North Carolina started to extend their common boundary to the west.
Knowing the location of the southern border of Virginia in the 1770's was essential for those planning to purchase land. Surveys had to be completed by authorized county surveyors, and filed in the appropriate county courthouse. Settlers wanted to know whether they should use Virginia or North Carolina courts to resolve disputes, and state officials wanted to receive tax revenue from those settlers.
Virginia was also determined to define the border in order to exert control over its territory. Land speculators tried to purchase whatever rights the Cherokees had to the land between the Kentucky and Cumberland rivers in the 1775 Treaty of Sycamore Shoals/Treaty of Watauga, and then create a new colony of Transylvania. The land south of southwestern Virginia, now the State of Tennessee, could have become the State of Franklin in 1784, if those counties had been able to obtain congressional support for that brief political initiative.
In 1779 Virginia and North Carolina appointed surveyors and commissioners to mark their joint boundary once again. Virginia was represented by Dr. Thomas Walker and General Daniel Smith, while Colonel Richard Henderson, William Bailey Smith, and John Williams represented North Carolina.
Both teams had representatives with strong personal agendas. Walker was active in the Loyal Land Company, with claims to 800,000 acres in western Virginia. Henderson was the prime mover behind the Transylvania effort, through which he had hoped to acquire title to 20 million acres. Virginia and North Carolina each ended up giving Henderson 200,000 acres to eliminate his claims and "quiet title" to the land grants issued by those states.
The boundary survey in 1779-80 started at the end of the Fry/Jefferson survey. The North Carolina representatives stopped at Cumberland Mountain, but the Virginia team went all the way to the Tennessee River.
According to a later lawsuit, the Virginia and Carolina commissioners/surveyors started in agreement, defining the latitude of 36° 30' to be a little over one mile south of where Fry and Jefferson had stopped their survey at Steep Rock Creek. After 45 miles, they reached Carters Valley near modern-day Kingsport, Tennessee. There, the North Carolinians concluded that the line being surveyed was located two miles to the south of 36° 30'. In their opinuon, Walker was trying to establish a claim to territory that belonged to North Carolina.1
Walker and the Virginia surveyors ignored the objections of the North Carolinians and kept blazing the "Walker Line" to the west. In hopes of resolving the disagreement, the North Carolinia members plus one Virginia commissioner (General Daniel Smith) moved north two miles and surveyed back towards Steep Rock Creek. However, Smith concluded halfway back that he had made a mistake and the original line was correct, so he rejoined Walker. The North Carolina surveyors and commissioners marked a separate "Henderson Line" from Steep Rock Creek to Cumberland Mountain, and went home.
Between Steep Rock Creek and Cumberland Gap, the two sets of surveyors created a two-mile gap between the Henderson Line on the south and the Walker Line on the north. In this "gore" of territory, legal authority was unclear and neither state could collect taxes effectively. 2
Walker, Smith and the Virginia surveyors kept surveying west beyond the Cumberland Gap, all the way to the Mississippi River. At Deer Fork, 124 miles west of their starting point at Steep Rock Creek, the Virginians skipped ahead 109 miles to the Cumberland River. There they determined through astronomical observations the latitude of 36 degrees 30 minutes, and surveyed 41 more miles west to the Tenneessee River. At the river, they ended up being over ten miles north of the desired 36° 30' - which would have benefitted North Carolina, had the commissioners/surveyors stayed with the project.
The debate about how to resolve the disputed Virginia-North Carolina boundary on its western end continued after both Virginia and North Carolina ceded control over that land to the independent states of Kentucky and Tennessee.
Kentucky lost territory to Tenneessee, due to the errors that caused the Walker Line to be located too far north. In 1820, Kentucky accepted the Walker Line as its boundary, but Tennessee gave Kentucky title to all the vacant land between 36° 30' and the Walker Line. The two states also agreed to move the boundary south to the 36° 30' parallel between the Tennessee-Mississippi rivers, to avoid repeating the error created by the Walker Line veering too far north on the eastern side of the Tennessee River.3
the Kentucky-Tennessee border was adjusted west of the Tennessee River to mitigate for errors made by the 1779-80 Walker Line survey
Source: ESRI, ArcGIS Online
If the 1665 decision by Charles II had been implemented, the Virginia-Tennessee border should match the 36° 30' parallel of latitude. In reality, the border is based on the inadequate expertise and equipment of the 18th Century, followed by lawsuits and political compromises.
The actual boundary is defined by on-the-ground marks and monuments - physical indications such as blazes on trees or stones placed into the earth - that were made by the surveyors. The ability of Global Positioning System (GPS) and Geographic Information System (GIS) technology to define the 36° 30' parallel more accurately is irrelevant in modern land ownership disputes.
Pioneer surveyors dragged iron chains west from the Atlantic Ocean, cutting a path through the natural vegetation and documenting the bearings/distances between monuments. In legal disputes since then, the monuments set on the ground are almost always defined as the property boundaries, no matter what documents may have said were supposed to be the dividing lines between colonies/states.
The southern boundary line of Virginia with Tennessee has curves and notches. The reasons for the shifts in the Virginia-Tennessee border are not clear. Suppositions include the effect on instruments of iron deposits in the Iron Mountains, in addition to the traditional tales about hard-drinking surveyors losing their sense of direction and strong-willed landowners convincing the surveyors to avoid cutting through pre-existing parcel boundaries.
One author concluded that many of the explanations for the adjustments were just made-up tales, and the most likely reason is that landowners requested boundary adjustments in order to keep their property in one state or the other. In his opinion, the large notch between North Carolina and Bristol was:5
In 1802, Virginia and Tennessee agreed to survey a compromise line. Each state would be given half the territory between the Henderson Line and the Walker Line. Commissioners for Virginia were Joseph Martin, Creed Taylor, and Peter Johnston. Commissioners for Tennessee were General John Sevier, Moses Fisk, and General Joseph Rutledge, and surveyors were Brice Martin and Nathan Markland. The Compromise Line of 1802 ran from Whitetop Mountain to Cumberland Gap. Martin and Markland marked blazes in a diamond pattern , so that 1802 survey is known as the "diamond line."6
At Virginia's southwestern tip, the boundary with Kentucky is based on the Walker Line. The Virginia/Tennessee boundary is based on the 1802 compromise between the Walker/Henderson lines, so it is located further south - creating a jog at the eastern end of the Tennessee/Kentucky line.7
Virginia tried to re-open the question of the boundary line location in 1858, 1870, and then again in 1887. Tennessee stuck to the 1802 compromise line, so the states ended up settling their boundary through a lawsuit.
Tennessee won the case. In 1893, the Supreme Court ruled in Virginia v. Tennessee:8
The Supreme Court decision confirmed that the line on the ground that had been the basis for election districts, tax collections, and real estate records was the boundary, no matter what the charter said. Virginia had benefitted from such reasoning in its dispute with Maryland over the low-water mark being the boundary along the Potomac River, and Virginia lost its claim to land in Tennessee by the same rationale:
The court case did clarify the mysterious notch in the boundary between North Carolina and Virginia at Bristol. When the 1802 line was resurveyed in 1901, the commissioners (who also served as the surveyors, in order to minimize cost) explored east and west of the notch. They looked for blazes on trees, in case the "compromise" surveyors had marked straight lines in the field in 1802, but then altered the location of the lines in their final report for some unknown reason.
The 1901 surveyors were able to find the distinctive diamond blazes from 1802, plus others remaining from an 1858 survey when Virginia tried to re-open the boundary question. In 1901, no marks were found on trees east or west of the notch that varied from the 1802 surveyors. The zig-zag boundary with a notch in the final 1802 compromise survey reflected the original field work.9
The Supreme Court case documented that the 1901 surveyors were confident that the 1802 effort had started from Burnt Hill. Defining that corner of Virginia/Tennessee was apparently the first compromise of that survey. Though the 1802 survey report says they started "on the summit of the mountain generally known as the White Top mountain," the line actually began on Burnt Hill, halfway between the top of White Top mountain and the Walker Line to the south.
Virginia did manage to convince Tennessee to make one adjustment in 1901. The 1802 line ran through Bristol, which had developed on both sides of the state boundary. (The Virginia side was originally the community of Goodson.) The state line was moved, in a bi-state agreement ratified by the US Congress, from the sidewalk on the northern side of the main street to the middle of the street.
This occurred after the "Water Works War of 1889." That dispute was triggered by a Tennessee-based water company trying to extend its lines to serve customers in Virginia, and a Virginia-based officer arrested the company president as he was working on the project. The Virginia-based utility then tried to construct its own pipeline down Main Street. Sheriffs from both Tennessee and Virginia brought their deputies to the scene, and the Tennessee sheriff raised a posse comitatus of several hundred volunteers.
Though violence was a real possibility, the "war" ended in a scene worthy of a Charlie Chaplin comedy episode. The Tennessee sheriff tried to serve a warrant on the Virginia officer who had arrested the president of the Tennessee company. The officer squirmed away, fell into the pipeline ditch - and the sheriff fell in on top of him. Another officer defused the situation, inviting them both to get up and go home until the lawyers could sort it out. 10.