Sir, these crowded galleries, these thronged lobbies, this full attendance of the Senate, prove the deep, transcendent interest of the theme. A few days only have elapsed since the Congress of the United States assembled in this Capitol. Then no agitation seemed to disturb the political elements. Two of the great political parties of the country, in their national conventions, had announced that slavery agitation was at an end, and that henceforth that subject was not to be discussed in Congress or out of Congress. The President, in his annual message, had referred to this state of opinion, and had declared his fixed purpose to maintain, as far as any responsibility attached to him, the quiet of the country. Let me read a brief extract from that message: "It is no part of my purpose to give prominence to any subject which may properly be regarded as set at rest by the deliberate judgment of the people. But while the present is bright with promise, and the future full of demand and inducement for the exercise of active intelligence, the past can never be without useful lessons of admonition and instruction. If its dangers serve not as beacons, they will evidently fail to fulfil the object of a wise design. When the grave shall have closed over all those who are now endeavoring to meet the obligations of duty, the year 1850 will be recurred to as a period filled with anxious apprehension. A successful war had just terminated. Peace brought with it a vast augmentation of territory. Disturbing questions arose, bearing upon the domestic institutions of one portion of the Confederacy, and involving the constitutional rights of the States. But, notwithstanding differences of opinion and sentiment, which then existed in relation to details and specific provisions, the acquiescence of distinguished citizens, whose devotion to the Union can never be doubted, had given renewed vigor to our institutions, and restored a sense of repose and security to the public mind throughout the Confederacy. That this repose is to suffer no shock during my official term, if I have power to avert it, those who placed me here may be assured." The agreement of the two old political parties, thus referred to by the Chief Magistrate of the country, was complete, and a large majority of the American people seemed to acquiesce in the legislation of which he spoke. A few of us, indeed, doubted the accuracy of these statements, and the permanency of this repose. We never believed that the acts of 1850 would prove to be a permanent adjustment of the slavery question. We believed no permanent adjustment of that question possible except by a return to that original policy of the fathers of the Republic, by which slavery was restricted within State limits, and freedom, without exception or limitation, was intended to be secured to every person outside of State limits and under the exclusive jurisdiction of the General Government.