I recd. on monday evening your favor of Mar. 23. with the return of Armstrong’s & Monroe’s letters first sent you. I cannot entirely despair that Spain notwithstanding the support given by France to her claim to W.F. may yield to our proposed arrangement, partly from its intrinsic value to her, partly from an apprehension of the interference of G.B. and that this latter consider may, as soon as France dispairs of her pecuniary object, transfer her weight into our scale. If she should persist in disavowing her right to sell W.F. to the U.S. and above all can prove it to have been the mutual understanding with Spain that W.F. was no part of Louisiana, it will place our claim on very different ground, such probably as could not be approved by the World, and Such certainly as could not with that approbation be contained by force.

If our right be good agst. Spain at all, it must be supported by those rigid maxims of technical law, which have little weight in national questions generally, and none at all when opposed to the principles of universal equity. The world would decide that France having sold us the territory of a third party, which she had no right to sell, that party having even remonstrated agst. the whole transaction, the right of the U.S. was limited to a demand on France to procure & convey the territory, or to remit pro tanto the price, or to dissolve the bargain altogether. I am pleased to find that Talleyrand’s letter is silent as to the W. Boundary. This circumstance is the more important as Monroe’s letter to which Talleyrand’s is an answer, expressly names the Rio Bravo as the W. limit of our claim.

The importance of some arrangement with Spain opening the Mobille to our trade, is sufficiently urged as in every event to be seriously pressed, in the instructions already in the hands of Monroe.

Inclosed are the letters from Cathalan which were sent me for perusal—a paper not before recd from Monroe—a letter from C. Pinkney—and two from Jarvis with their inclosures, except the letters from the forger of draughts in Preble’s name, which have been put into the hands of the Secy. of the Navy; & a letter from Dr. Lattimore

Yrs. with respectful attachment