Envisaging the West: Thomas Jefferson and the Roots of Lewis and Clark


Letter from Thomas Jefferson to Thomas Walker and Daniel Smith

Thomas Jefferson To Thomas Walker and Daniel Smith, January 29, 1780
In this secret communique, Thomas Jefferson instructs the surveyors to assist George Rogers Clark in selecting a spot for the fort to be constructed at the falls of the Ohio River.

Wmsburg Jany. 29th 1780


As we propose this Spring to take possession of and fortify some post as near the mouth of Ohio Maps: as the ground will admit, it becomes very important for us to know the exact latitude thereabouts. I take it for granted that your present Line will be stopped before you get there by unpurchased Lands. We therefore wish extremely that one of you would take a trip to the mouth of the Ohio Maps: with your instruments immediately on finishing your present work. I suppose it will be best for you to go to the falls of the Ohio where Col. Clarke has orders to furnish you with Assistants, an Escort and all necessaries. You will first find the point at which our Line strikes the Missisippi Maps: or Ohio Maps: , and fix it by some lasting immoveable natural mark if there happen to be any on the spot, or if not, then by its course and distance from some such natural mark, noting such course as corrected from the errors of variation, and the distance reduced to horizontal measure. The reason of requiring this accuracy in fixing the point where our Line strikes is, that in future, with common instruments it will be easy to find it which may perhaps be of importance. When you have found this point if it be on the Missisippi Maps: run from thence along up the river to the mouth of Ohio, and by protraction fix the point of the forks or if it be on the Ohio Maps: , run up that river to where good Clifts for fortification shall make in and as you go along note the high ground points or Clifts on the river which appear to you capable of Works of defence and at the same time to command a view of the river. This done I would ask the favor of you to return one plat of your work to Col. Clarke and another to me. Col. Clarke has in his eye a particular Cliff on the Missisippi Maps: which he expects is the nearest good ground for fortification. This he will describe to you, and you will please to note it particularly. I am in hopes that it will suit one of you to undertake this business. We think to have the fort begun, which cannot be till we are assured that the ground we should pitch on is within our own Country. The disappointment will therefore be of the greatest moment should you decline the Service.

I am Genti. with the greatest respect Your most obedt. Hmble Servt.