Historical Notes: The best description of Peter Jefferson's role in the creation of the Map of Virginia came from his son:
"My father's education had been quite neglected; but being of a strong mind, sound judgment and eager after information, he read much and improved himself insomuch that he was chosen with Joshua Fry professor of Mathem. In W.[William] and M.[Mary] college to continue the boundary line between Virginia and N. Caroline...and was afterwards employed with the same Mr. Fry to make the 1st accurate map of Virginia which had ever been made, that of Capt. Smith being merely a conjectural sketch. They possessed excellent materials for so much of the country as is below the Blue Ridge, little being known beyond that ridge."
Jefferson was eight years old when his father finished his work on this map, and its importance seems to have been indelibly marked in his mind. Regardless of filial pride, the Fry-Jefferson map was the most accurate record of Virginia in the eighteenth century, and Jefferson used it as the basis for the map he compiled for "Notes on the State of Virginia".
Joshua Fry and Peter Jefferson were commissioned to draw a map of Virginia by the acting Virginia governor, Lewis Burwell, in 1750. The two men were obvious candidates for the job. Both were proven surveyors and established landholders in Albemarle County. They formed a kind of partnership, with the more prominent Fry attracting commissions, and the capable Jefferson carrying out much of the work.
They first began working together in 1746, when in his post as commissioner of the Crown, Fry caused Jefferson to be chosen as one of four surveyors to map the boundaries of Virginia's Northern Neck. Although Jefferson already had considerable surveying experience, working with Fry probably contributed to his knowledge of mathematics. Their next project, in 1749, was a survey to extend the dividing line between North Carolina and Virginia. The men met with great hardships as they crossed mountains and rivers, and tales of their journey were passed down to Thomas Jefferson's great grand-children:
"Colonel Jefferson and his companions had often to defend themselves against the attacks of wild beasts during the day, and at night found but a broken rest, sleeping - as they were obliged to do for safety - in trees...Jefferson's courage did not once flag, but living upon raw flesh, or whatever could be found to sustain life, he pressed on and persevered until his task was accomplished."
These two projects laid the groundwork for their map of Virginia, published first in England in 1752. It was to be their last collaboration.
The two men went separate ways after the map's publication. Jefferson returned to his Shadwell farm, and Fry was appointed commander-in-chief of the Virginia Forces. Jefferson became an Albemarle County magistrate, and after Fry's death in 1754 assumed his offices as county surveyor and member of the House of Burgesses. Fry bequeathed his surveying tools to Peter Jefferson, and some of these tools were undoubtedly among the mathematical instruments that Thomas Jefferson inherited from his father, along with a map of the state of Virginia. This map was probably lost in the fire at Jefferson's birthplace, Shadwell, in 1770. Jefferson likely owned several copies of his father's map, and this later 1775 edition may have been the one that hung in the Entrance Hall at Monticello.