From Virginia reports: Jefferson--33 Grattan, 1730-1880:
JUDGE ROANE. About the year 1768 and 1769, Doctor Thomas Walker, who had a large tract of vacant land in the County of Washington, and wished to sell it out to settlers, published his price and terms therefor, in advertisements stuck up at two or three places in the Western Country. In consequence of these proposals, many persons went out and actually settled on the lands; and among *others, James Piper, Joseph Black, Christopher Acklin, Josias Gamble, Alexander Breckenbridge, and John Campbell, (who have all given depositions in this cause,) and John Huston, under whom the appellant claims.... .
The Vance vs. Walker lawsuit in the Court of Appeals.
Doctor Thomas Walker, who married 2nd Mildred (Thornton) Meriweather, widow of Nicholas Meriweather, maintained a journal (1749/50) of his travels.
The route of Dr. Thomas Walker, the explorer, through the Cumberland Gap can be seen here.
Background of Dr. Walker and the Loyal Company: "Later in 1749, Peter Jefferson (father of future U.S. President Thomas Jefferson) and Joshua Fry, along with Dr. Thomas Walker of Albemarle County (1714-1794), James Maury, Thomas Meriwether (grandfather of Meriwether Lewis) and others, established the Loyal Company with the purpose of petitioning for a large grant of land west of the Allegheny Mountains." [Source: journal link at TnGenWeb]
The plans of the Loyal Company and other land speculators encountered a glitch in the form of King George's Proclamation Line of 1763.
From History of pioneer Kentucky:
... In 1749 the Loyal Land Company was formed and given eight hundred thousand acres to be located indefinitely in the west north of 36 (degrees) 30.
The Loyal Land Company though the last to be organized was the first to begin work. In the winter of 1749 they commissioned Dr Thomas Walker of Albemarle County Virginia to explore the western country and report concerning its character. Dr Walker began his journey in March 1750 notwithstanding the bad season.
From History of Southwest Virginia, 1746....