I have just recd. from Mr. Monroe a very extraordinary communication confidentially made to him by Col: Jessup.1 A copy of it is inclosed. An invasion by a Spanish force at the present period might be pronoun[c]ed a mere chimæra, if a less degree of folly reigned at Madrid; unless indeed the Councils of Spain shd be supported by a power whose councils may reasonably be more confided in. It is probable however that Onis is intriguing at N. Orleans, and the extent to which he may mislead, an ignorant proud & vindictive Govt. cannot be calculated. It is incumbent on us therefore to have an eye to our S. W. Frontier, proportioning our precautions to our means, and to a fair estimate of the danger. As Gen: Jackson is apprized of the apprehensions of Col: Jessup tho’ without some of the grounds of them mentioned to Mr. Monroe, we may expect soon to hear from him on the subject. Are there any reinforcements or defences, which can be added to those now within his employment? Should Jessup execute his purpose, it will be the boldest project, ever assumed by no higher authority. I communicate the intelligence he gives, to the Secy. of the Navy. Be so good as to do the same to your Colleagues at Washington