Your faithful friend,

George Bancroft.

Mr. Buchanan had already determined what course to advise the President to pursue in regard to Mexico. This was to re-establish diplomatic relations with her, by sending a minister with special instructions and authority to negotiate a settlement of all questions between the two countries, including the western boundary of Texas. To select a suitable person for this mission and send him into Mexico with an uncertainty of his being received, or of his being received and treated with, was a delicate matter. The appointment had to be made, and to be kept a profound secret, until it could be known what reception the minister would meet with. It was settled early in the autumn that this appointment should be offered to Mr. John Slidell of Louisiana. His acceptance of the position was made known to the President in September. The following private letter to Mr. Buchanan is somewhat amusing in its earnestness respecting the secrecy which had been enjoined upon the writer:[[102]]

[MR. SLIDELL TO MR. BUCHANAN.]

New Orleans, Sept. 25, 1845.

My Dear Sir:—

You can scarcely imagine how much I was surprised to-day by receiving your most kind and friendly letter of the 17th inst.

I have never at any time believed that we should have war with Mexico. I have looked upon the rhodomontades of the press and the manifestoes of secretaries, as alike having but one object in view, the presidential contest; and in this point of view I consider it of little consequence who shall be elected. He who had been most strenuous in proclaiming war as indispensable to the vindication of Mexican honor, would, when installed in the presidential chair, “roar you an ’twere any nightingale.” The truth is that although I have no very exalted idea of ...... yet I cannot imagine that any one who could possibly be elected president, could have so small a modicum of sense as to think seriously of going to war with the United States. But strong as I have been in this belief, I had not thought that the government would have been prepared so soon to receive from us an accredited agent. I think with you that they desire to settle amicably all the questions in dispute between us. But will they dare in the present distracted state of the country, to give so great a shock to what is their settled public opinion. They have stimulated popular prejudice to a degree that it may, under any appearance of disposition to treat with us, be fatal to the new administration. But of this you have infinitely the best means of judging, and I shall hold myself in readiness to receive your instructions. I feel most deeply the importance of the mission, and I confess, now that it is probable I shall soon enter upon it, I have some misgivings about it. I hope that you will not consider this as an affectation of modesty and humility. I assure you I am perfectly sincere, but will probably grow in better favor with myself when the work is fairly commenced. I am truly grateful to you for the proof of your friendship and esteem, and am flattered by the confidence reposed in me by the President. I shall endeavor to justify them. The President has enjoined on me the strictest secrecy; he even goes so far as to say that I should not communicate what he had said to me to a single human being. I have told him that I was obliged to make an exception in favor of Mrs. S., but as I could not well enter into particulars with him on this subject, pray let me explain it to you. If I had made an unreserved pledge to the President, I could not have felt myself at liberty to hint it even to my wife. I could have made no preparations for my voyage without her knowing it. We were making our arrangements to proceed shortly to Washington. If I were mysterious with her, she would be shrewd enough to guess what was in the wind. She would have some theory to guide her, because you may recollect that when you first broached this subject with me, I told you that I had no secrets for her. Now I am not one of those who believe that a woman cannot keep a secret. I know she can, for I am sure that she has never breathed a word, respecting it, to any one, not even to her mother. Besides she is living in the country, where we seldom see any one, and where there is little gossiping. Pray, explain this to the President, who might perhaps consider my disobedience of his injunction as an inauspicious omen in the opening of my diplomatic career. It is a matter of great regret to me not to have the opportunity of full personal communication with you before going to Mexico. I feel that it will be a great disadvantage, but I must rely upon your alleviating it as far as possible by your communications and instructions.... I will not fail to convey your very flattering message to Mrs. S. I think I must get her to write to you to remove an impression which I fear you have taken up. She will tell you that I am one of the best tempered men living. I have written in great haste, having barely had time to save the mail.

Believe me, my dear sir, most truly and respectfully,

Your friend and servant,