The convention you have the honor to represent was pleased to refer to my views respecting the institution of slavery. Some of these views were partly expressed in the remarks made by me in the House of Representatives, on the 30th of June last; in the letter to my constituents before referred to; and in my arguments before the _Criminal_ Court of the District of Columbia, in the “Pearl” cases. These, and kindred views, I shall improve all fitting opportunities that I may ever enjoy to enlarge upon and enforce; and had I the tongue of an angel, or the pen of inspiration, I believe I could use them on no holier theme than in kindling abhorrence at the wrongs suffered by the slave, and in melting the universal heart of humanity into pity for his lot; for I hold it to be impossible for the soul of a slave,--benighted, strangled, and buried alive as it is,--ever fully to know and feel the joys of that spiritual liberty wherewith Christ maketh his disciples free. Be pleased, gentlemen, to accept my thanks for the very kind manner in which you have made known to me the decision of the convention you represent, and believe me, Very truly and sincerely, yours, &c., &c., HORACE MANN. SPEECH DELIVERED IN THE HOUSE OF REPRESENTATIVES OF THE UNITED STATES, FEBRUARY 23, 1849, ON SLAVERY AND THE SLAVE TRADE IN THE DISTRICT OF COLUMBIA. MR. CHAIRMAN; There is a bill upon the speaker’s table which provides for abolishing the slave trade in the District of Columbia. For three successive days we have tried in vain to reach it, in the order of business. Its opponents have baffled our efforts. Our difficulty is not in carrying the bill, but in reaching it. I am not without apprehension that the last sands of this Congress will run out, without any action upon the subject. Even should the bill be taken up, it is probable that all debate upon it will be suppressed by that sovereign silencer,--the previous question. Hence I avail myself of the present opportunity, as it is probably the only one I shall have, during the present session, to submit my views upon it. I frankly avow, in the outset, that the bill provides for one part only of an evil, whose remedy, as it seems to me, is not only the object of a reasonable desire, but of a righteous and legal demand. The bill proposes the abolition, not of slavery, but only of the slave trade, in the District of Columbia. My argument will go to show, that, within the limits of this District, slavery ought not to exist in fact, and does not exist in law. Sir, in the first place, let us inquire what is the state of things in this District on this subject. The gentleman from Indiana, [Mr. R. W. THOMPSON,] who addressed us a few days since, used the following language:--