DEAR SIR,

I have receiv’d your letter of the 14th containing a very interesting view of the late treaty with Spain, and of the proceedings respecting it here. If the occurrence involv’d in it nothing more, than a question between the United States 8 and Spain, or between them & the Colonies, I should entirely concur in your view of the subject. I am satisfied, that we might, regulate it, in every circumstance, as we thought just, & without war, that we might take Florida as an indemnity, and Texas for some trifle as an equivalent. Spain must soon be expelled from this Continent, and with any new gov’t. which may be form’d in Mexico, it would be easy to arrange the boundary in the wilderness, so as to include as much territory on our side as we might desire. No European power could prevent this, if so disposed. But the difficulty does not proceed from these sources. It is altogether internal, and of the most distressing nature and dangerous tendency. You were apprized by me, on your return from Europe, of the true character, of the negotiation, which took place in 1785-6. with the Minister of Spain, for shutting up the mouth of the Mississippi, a knowledge of which might have been deriv’d in part from the secret journal of Congress, which then came into your hands. That, was not a question with Spain, in reality, but one among ourselves, in which her pretensions were brought forward, in aid of the policy, of the party at the head of that project. It was an effort to give such a. shape to our Union, as would secure the dominion over it, to its eastern section. It was expected that dismemberment by the Allegheny Mountains, would follow the occlusion of the river, if it was not desir’d, tho’ the latter was then & still is my opinion. The Union then consistedof eight navigating and commercial States, with five productive, holding slaves; and had the river been shut up, and dismemberment insured, the division would always have been the same. At that time Boston ruled the four New England States, and a popular orator in Fanuel hall, ruled Boston. Jays object was to make N. York a New England State, which he avowed on his return from Europe, to the dissatisfaction of many in that State, whose prejudices had been excited in the revolutionary war by the contest between N. York and those States respecting interfering grants in Vermont. It was foreseen by these persons, that if the Mississippi should be open’d, and new States be established on its waters, the population would be drawn thither, the number of productive States be proportionally encreased, & their hope of dominion, on that contracted sectional scale, be destroyed. It was to prevent this that that project was formed. Happily it failed, & since then, our career, in an opposite direction, has been rapid & wonderful. The river has been open’d, & all the territory dependant on it acquir’d, eight states have already been admitted into the Union, in that quarter; a 9th is on the point of entering, & a provided for, exclusive of Florida. This march to greatness has been seen with profound regret, by them, in the policy suggested, but it has been impelled by causes over which they have had no control. Several attempts have been made to impede it, among which, the Harford Convention in the late war, and the proposition for restricting Missouri, are the most distinguished. The latter measure contemplated, an arrangement on the distinction solely, between slave holding and non­-slave holding States, presuming that on that basis only, such a division might be formed, as would destroy, by perpetual excit’ment, the usual effects proceeding from difference in climate, the produce of the soil, the pursuits and circumstances of the people, and marshall the States, differing in that circumstance, in unceasing opposition & hostility with each otherTo what account, this project, had it succeeded, to the extent contemplated, might have been turn’d, I cannot say. Certain however it is, that since 1786, I have not seen, so violent & persevering a struggle, and on the part of some of the leaders in the project, for a purpose so unmasked & dangerous. They did not hesitate to avow that it was a contest for power only, disclaiming the pretext of liberty, humanity, It was also manifested, that they were willing to risk the Union, on the measure, if indeed, as in that relating to the Mississippi, dismemberment was not the principal object. You know how this affair terminated, as I presume you likewise do, that complete success, was prevented, by the patriotic devotion of several members in the non slave holding States, who preferr’d the sacrifice of themselves at home, to a violation, of the obvious principles of the Constitution, & the risk of the Union. I am satisfied that the arrangement made, was most auspicious for the Union, since had the conflict been pursued, there is reason to believe that the worst consequences would have followed. The excitement would have been kept up, during which it seemed probable, that the slave holding States would have lost ground daily. By putting a stop to the proceeding, time has been given for the passions to subside, & for calm discussion & reflec­tion, which have never failed to produce their proper effect in our country. Such too was the nature of the controversy, that it seem’d to be hazardous, for either party to gain a complete triumph. I never doubted the right of Congress, to make such a regulation in [the] territories, tho’ I did not expect that it would ever have been exercised.

From this view, it is evident, that the further acquisition, of territory, to the West and South, involves difficulties, of an internal nature, which menacethe Union itself. We ought therefore to be cautious in making the attempt. Having secur’d the Mississippi, and all its waters, with a slight exception only, and erected States there, ought we not to be satisfied, so far at least as to take no step in that direction, which is not approved, by all the members, or at least a majority of those who accomplished our revolution. I could go into further details had I time. I have thought that these might afford you some satisfaction. When we meet in Albemarle we will communicate further on the subject.