[Inclosure.]

WAR DEPARTMENT,

Washington, February 18, 1861.

To the PRESIDENT:

SIR: On the 11th of February the House of Representatives adopted a resolution requesting the President, if not incompatible with the public interests, to communicate "the reasons that had induced him to assemble so large a number of troops in this city, and why they are kept here, and whether he has any information of a conspiracy upon the part of any portion of the citizens of this country to seize upon the capital and prevent the inauguration of the President-elect." This resolution having been submitted to this Department for consideration and report, I have the honor to state that the body of troops temporarily transferred to this city is not large, as is assumed by the resolution, though, it is a well-appointed corps and admirably adapted for the preservation of the public peace. The reasons which led to their being assembled here will now be briefly stated.

I shall make no comment upon the origin of the revolution which for the last three months has been in progress in several of the Southern States, nor shall I enumerate the causes which have hastened its advancement or exasperated its temper. The scope of the question submitted by the House will be sufficiently met by dealing with the facts as they exist, irrespective of the cause from which they have proceeded. That revolution has been distinguished by a boldness and completeness of success rarely equaled in the history of civil commotions. Its overthrow of the Federa authority has not only been sudden and widespread, but has been marked by excesses which have alarmed all, and been sources of profound humiliation to a large portion of the American people. Its history is a history of surprises and treacheries and ruthless spoliations. The forts of the United States have been captured and garrisoned and hostile flags unfurled upon their ramparts. Its arsenals have been seized, and the vast amount of public arms they contained appropriated to the use of the captors, while more than half a million of dollars found in the mint at New Orleans has been unscrupulously applied to replenish the coffers of Louisiana.

Officers in command of revenue-cutters of the United States have been prevailed on to violate their trust and surrender the property in their charge, and, instead of being branded for their crimes, they and the vessels they betrayed have been corially received into the service of the seceded States.

These movments were attended by yet more discouraging indications of immorality. It was generally believed that this revolution was guided and urged on by men occupying the highest positions in the public service, and who, with the responsibilities of an oath to support the Constitution still resting upon their consciences, did not hesistate secretly to plan and openly to labor for the dismemberment of the Republic whose honors they enjoyed and upon whose Treasury they were living. as examples of evil are always more potent than those of good, this spectacle of demoraliztion on the part of States and statesmen could not fail to produce the most deplorable consequences. The discontented and the disloyal everywhere took courage. In other States adjacent to and supposed t sympathize in sense of political wrong with tose referred to revolutionary shemes were set on foot, and forts and arms of the United States seized. The unchecked prevalence of the revolution and the intoxication which its triumphs inspired naturally suggested wilder and yet more desperate enterprises