thanks for the Chart of the coast of Florida, & mouth of the Missisipi which he has been so good as to send him. at a time when we are endeavoring to acquire exact knolege of that country, in order to make our first arrangements understandingly, so accurate a chart whose existence was not before known here, is doubly precious …
To William Marshall, December 24, 1803
Patrick Lee’s Explanation
Smart leaders appreciate those who make everyone smarter.
Marshall, a South Carolina lawyer, had come into possession of a map which he claimed to be an accurate chart of the coast of West Florida (the panhandle), the coast of Louisiana, and the mouth of the Mississippi River, plus river depth soundings some distance north of New Orleans. He forwarded that map to the President.
Accurate knowledge about Louisiana in 1803 was as miniscule as the territory was large. Anything that expanded its documentation was like gold to Jefferson. He contended the purchase of Louisiana, vast lands west of the Mississippi, also included some land on the east side of that river known as West Florida. That portion was the Gulf Coast east to the Perdido River, the current boundary between Alabama and Florida. This map provided additional intelligence toward that end.