By the summer of 1777, George Washington had identified a definite weakness in the Army’s ability to produce adequate topographical data in order to plan and execute theater operations. In July of that year, Washington wrote to Congress, “A good geographer to Survey the Roads and take Sketches of the Country where the Army is to Act would be extremely useful… …I would beg leave to recommend Mr. Robt. Erskine…”
“Young gentlemen of Mathematical genius, who are acquainted with the principles of Geometry, and who have a taste for drawing, would be the most proper assistants for a Geographer. Such, in a few days practice, may be made expert surveyors. The instrument best adapted for accuracy and dispatch is the Plain-Table; by this, the Surveyor plans as he proceeds, and not having his work to protract in the evening may attend the longer to it in the day. One of these instruments, with a chain and ten iron-shod arrows, should be provided for each of the Surveyors it may be thought proper to employ.”
Robert Erskine to George Washington, August 1, 1777