To Thomas Jefferson from William Dunbar, 30 September 1803
From William Dunbar
Natchez 30th. September 1803
Dear Sir
I had the pleasure of writing you the 19th. of last month, inclosing such imperfect information on the subject of your queries, as I at that time possessed; since which I have been favored with the perusal of the result of Mr. Clark’s researches, which are, as I expected, ample, leaving nothing more to be desired respecting most of the points of enquiry; He informs me also that he procured a chart of the Western province to be sketched and sent to you: this notice supercedes the necessity of my furnishing you with any thing at the present moment on the same subject. I shall shortly receive a Copy of the same Chart, & should I find room for improvement, which it may be in my power to bring forward, I shall new model the whole and forward it to you: I perceive a difference of our statements respecting militia, but this is to be reconciled by taking Mr. Clark’s as the roll of the militia contained in the Government Registers and mine as the number of men from 18 to 45 years able to bear arms, to which Mr. Clark assents. It is probable that Mr. Clark’s information is better than mine respecting the extent of Louisiana along the Sea coast; but I have had reason to suppose that the waters of the inundation extended upon the Coast 3° of longitude & that from thence to the river Sabine was considerably less.
The Gentleman who was to have been entrusted with the scientific part of the Spanish Commission for running the boundary line between Louisiana and the Spanish territory, writes in answer to my inquiries as follows. ‘You have devined the real cause of our commissioners remaining inactive; the news of the cession of the province (tho’ not official) shackles them in their operations, and will not allow them to adopt any decisive measures, and for this reason they have not yet determined on any thing concerning the instruments that may be wanted, should it be necessary to run a line, which it is generally expected will not be the case; for it is presumed that the two Floridas will be given to the United States by Spain in exchange for the west side of the Missisippi. The Spanish Commissioners had not, nor have they as yet come to any determination, as to the method and principles, on which the line of demarkation ought to be run, neither has any point of the line been defined except one, which is two leagues from Nachitoches W.S.W. on the road to Nacokdoches, the most eastern post of the province of Texas; formerly the Spaniards had a fort at the Adaïs, five leagues west (nearly) from the bayu de Laurier, which is the place where the line crosses the road from Natchitoches to Nakogdoches. It is generally understood here, that the limits of Louisiana are not defined in the treaty of cession by Spain to France, and this conjecture is warranted by the instructions transmitted by our Court to the Commissioners, wherein among a variety of Objects relative to the cession, they are ordered to determine and run the boundary line, and no data given them by which they can be guided in the Operation.’
I possess a sketch taken from a chart in the possession of the Spanish government, where the boundary line is represented quitting the Sabine river in a direction nearly E.N.E. to a point distant about 2 leagues from the red river, thence making a right angle with the last course in the direction of nearly W.N.W. (including the post of Adaïs within the angle) was drawn an indefinite line, which appears to have been intended as a parallel to the general course of the red river at that place. Hence it is fair to conclude that this parallel to the red river ought to be continued to the northern Andes, from which chain of mountains the Red river and Messouri derive their Sources; the western boundary consequently will be along this natural division of the middle from the western waters to the Latitude (perhaps) of the Lake of the Woods.1
I am with the highest respect Your Obedient & devoted Servant
William Dunbar
RC (DNA: RG 59, TP, Orleans); endorsed by TJ as received 23 Oct. and so recorded in SJL; also endorsed by a clerk. FC (Lb in Ms-Ar: William Dunbar Papers); dated 29 Sep.; printed in Eron Opha Moore Rowland (Mrs. Dunbar Rowland), ed., The Life, Letters and Papers of William Dunbar (Jackson, Miss., 1930), 124-5.
mr. clark’s researches: most of the information that Daniel Clark compiled in response to TJ’s queries on Louisiana he directed to Madison, sending letters and detailed enclosures to the secretary of state on 8 and 29 Sep. (, 9:28-47, 61-6).
chart of the western province: see Daniel Clark to TJ, 18 Aug.
Answering TJ’s query number 7, Clark copied an official Spanish return of militia units in Louisiana that came to a total of 5,440 men. Dunbar, in his retained copy of the letter printed above, estimated that 10,000 men met the criteria for militia service (, 9:33-4; Rowland, William Dunbar, 124).
along the sea coast: responding to the president’s third and fourth queries, which supposed that the Piakemines River (Bayou Plaquemine) formed the “western mouth” of the Mississippi, Clark stated that the westernmost mouth of the Mississippi was the Atchafalaya River, into which the Plaquemine flowed. Clark stated that the distance along the coast from the mouth of the Atchafalaya to the bay into which the Sabine River emptied was about three degrees of longitude and that the direct distance west from the Plaquemine to the Sabine, which was “the supposed Western Boundary of Louisiana,” was also about three degrees of longitude (, 9:31).
The gentleman of Dunbar’s acquaintance who was to have been part of the spanish commission to mark the boundary between Spanish and French possessions was Stephen Minor. He had been the leading commissioner for Spain in Andrew Ellicott’s survey of the southern border of the United States. Originally from the area that became western Pennsylvania, Minor served as an officer in the Spanish army during the American Revolution and remained in the service of Spain after he settled at Natchez (Arthur H. DeRosier, Jr., William Dunbar: Scientific Pioneer of the Old Southwest [Lexington, Ky., 2007], 126; Jack D. L. Holmes, Gayoso: The Life of a Spanish Governor in the Mississippi Valley, 1789-1799 [Baton Rouge, La., 1965], 147n, 198-9, 232-4; Rowland, William Dunbar, 132-3).
northern andes: the Rocky Mountains.
1. In FC Dunbar continued: “Should it be found necessary to run a line of demarcation I would suggest the impropriety of sending white laborers with the commission from the Seat of Govt. as in the Case of Mr Ellicot—negroes hired here will be more tractable & will execute much more labor—a proof which we had upon the line of 31°.”