Department of State, January 16, 1861.

Lieutenant-General Winfield Scott:

Dear General: The habitual frankness of your character, the deep interest you take in everything that concerns the public defense, your expressed desire that I should hear and understand your views—these reasons, together with an earnest wish to know my own duty and to do it, induce me to beg you for a little light, which perhaps you alone can shed, upon the present state of our affairs.

1. Is it the duty of the Government to re-enforce Major Anderson?

2. If yes, how soon is it necessary that those re-enforcements should be there?

3. What obstacles exist to prevent the sending of such re-enforcements at any time when it may be necessary to do so?

I trust you will not regard it as presumption in me if I give you the crude notions which I myself have already formed out of very imperfect materials.

A statement of my errors, if errors they be, will enable you to correct them the more easily.

It seems now to be settled that Major Anderson and his command at Fort Sumter are not to be withdrawn. The United States Government is not to surrender its last hold upon its own property in South Carolina. Major Anderson has a position so nearly impregnable that an attack upon him at present is wholly improbable, and he is supplied with provisions which will last him very well for two months. In the meantime Fort Sumter is invested on every side by the avowedly hostile forces of South Carolina. It is in a state of siege. They have already prevented communication between its commander and his own Government, both by sea and land. There is no doubt that they intend to continue this state of things, as far as it is in their power to do so. In the course of a few weeks from this time it will become very difficult for him to hold out. The constant labor and anxiety of his men will exhaust their physical power, and this exhaustion, of course, will proceed very much more rapidly as soon as they begin to get short of provision.

If the troops remain in Fort Sumter without any change in their condition, and the hostile attitude of South Carolina remains as it is now, the question of Major Anderson’s surrender is one of time only. If he is not to be relieved, is it not entirely clear that he should be ordered to surrender at once? It having been determined that the latter order shall not be given, it follows that relief must be sent him at some time before it is too late to save him.

This brings me to the second question: When should the re-enforcements and provisions be sent? Can we justify our-selves in delaying the performance of that duty?

The authorities of South Carolina are improving every moment, and increasing their ability to prevent re-enforcement every hour, while every day that rises sees us with a power diminished to send in the requisite relief. I think it certain that Major Anderson could be put in possession of all the defensive powers he needs with very little risk to this Government, if the efforts were made immediately; but it is impossible to predict how much blood or money it may cost if it be postponed for two or three months.

The fact that other persons are to have charge of the Government before the worst comes to the worst has no influence upon my mind, and, I take it for granted, will not be" regarded as a just element in making up your opinion. " The anxiety which an American citizen must feel about any future event which may affect the existence of the country, is not less if he expects it to occur on the 5th of March than it would be if he knew it was going to happen on the 3d.

I am persuaded that the difficulty of relieving Major Anderson has been very much magnified to the minds of some persons. From you I shall be able to ascertain whether I am mistaken or they. I am thoroughly satisfied that the battery on Morris Island can give no serious trouble. A vessel going in where the Star of the West went will not be within the reach of the battery's guns longer than from six to ten minutes. The number of shots that could be fired upon her in that time maybe easily calculated, and I think the chances of her being seriously injured can be demonstrated, by simple arithmetic, to be very small. A very unlucky shot might cripple her, to be sure, and therefore the risk is something. But then it is a maxim, not less in war than in peace, that where nothing is ventured nothing can be gained. The removal of the buoys has undoubtedly made the navigation of the channel more difficult. But there are pilots outside of Charleston, and many of the officers of the Navy, who could steer a ship into the harbor by the natural landmarks with perfect safety. This, be it remembered, is not now a subject of speculation; the actual experiment has been tried. The Star of the West did pass the battery, and did overcome the difficulties of the navigation, meeting with no serious trouble from either cause. They have tried it; we can say probatum est; and there is an end to the controversy.

I am convinced that a pirate, or a slaver, or a smuggler, who could be assured of making five hundred dollars by going into the harbor in the face of all the dangers which now threaten a vessel bearing the American flag, would laugh them to scorn, and to one of our naval officers who has the average of daring, ' the danger's self were lure alone! '

There really seems to me nothing in the way that ought to stop us except the guns of Fort Moultrie. If they are suffered to open a fire upon a vessel bearing re-enforcements to Fort Sumter, they might stop any other vessel as they stopped the Star of the West. But is it necessary that this intolerable outrage should be submitted to? Would it not be an act of pure self-defense on the part of Major Anderson to silence Fort Moultrie, if it be necessary to do so, for the purpose of insuring the safety of a vessel whose arrivalat Fort Sumter is necessary for his protection, and could he not do it effectually ? Would the South Carolinians dare to fire upon any vessel which Major Anderson would tell them beforehand must be permitted to pass, on pain of his guns being opened upon her assailants ? But suppose it impossible for an unarmed vessel to pass the battery, what is the difficulty of sending the Brooklyn or the Macedonian in ? I have never heard it alleged that the latter could not cross the bar, and I think if the fact had been so it would have been mentioned in my hearing before this time. It will turn out upon investigation, after all that has been said and sung about the Brooklyn, that there is water enough there for her. She draws ordinarily only sixteen and one-half feet, and her draught can be reduced eighteen inches by putting her upon an even keel. The shallowest place will give her eighteen feet of water at high tide. In point of fact, she has crossed that bar more than once. But apart even from these resources, the Government has at its command three or four smaller steamers of light draught and great speed, which could be armed and at sea in a few days, and would not be in the least troubled by any opposition that could be made to their entrance.

It is not, however, necessary to go into the details, with which, I presume, you are fully acquainted. I admit that the state of things may be somewhat worse now than they were a week ago, and are probably getting worse every day; but is not that the strongest reason that can be given for taking time by the forelock?

I feel confident that you will excuse me for making this communication. I have some responsibilities of my own to meet, and I can discharge them only when I understand the subject to which they relate. Your opinion, of course, will be conclusive upon me, for on such a matter I cannot do otherwise than defer to your better judgment. If you think it most consistent with your duty to be silent, I shall have no right to complain.

If you would rather answer orally than make a written reply, I will, meet you either at your own quarters or here in the State Department, as may best suit your convenience.

I am, most respectfully, yours, &c,

J. S. Black.