On 2 January 1808, the General Assembly of Virginia passed an act altering the boundaries of Giles County to be in force from 1st March 1808:

"Be it enacted by the general assembly, That all that part of the county of Wythe, which lies within the following bounds, to wit: Beginning on the line of said county, on the top of Walker's mountain, where the line of division between the counties of Montgomery and Giles strikes the line of Wythe county, thence running along the top of the said mountain southwesterly to a place called the Blue or Big Rock, thence from the said Blue or Big Rock, running across the valley of Walker's creek, in a direction parallel to the present line of division between Giles and Wythe, to the line of Tazewell county, thence with the line of Tazewell to the line of Giles, and along the present line of Giles to the beginning, shall be, and the same is hereby added to, and made a part of the said county of Giles; and the militia within the said bounds shall hereafter compose a part of the same regiment as the militia of the other parts of the county of Giles."

Samuel Shepherd, The Statutes at Large of Virginia, Vol 3, p. 389.