I am familar with that speech, but you are assuming that Jefferson was referring to the all races, when he said that "all men are created equal" in the Declaration of Independence. He wasn't. He was a slaveowner in every sense of the word, refusing to free even his own children!
Now his quote: "The prevailing ideas entertained by him and most of the leading statesmen at the time of the formation of the old constitution, were that the enslavement of the African was in violation of the laws of nature; that it was wrong in principle, socially, morally, and politically." States that most of the founding fathers were opposed to slavery, yet a good many of them also kept slaves......
So I don't believe that Stephens was disavowing the Declaration of Independence in this speech, though possibly the Constitution.
Do you have any more examples?
Jeffersonian historians would vehemently disagree with you and argue that Jefferson and the great majority of the Founders did in fact mean that "all," including Blacks, were created equal under the law. (Don't confound the Founders views on social equality with what they thought about legal equality) That they could not at that point deal with the incongruity of slavery with their principles was a talked about by many and as Stephens said in 1861, all expected (or hoped) that slavery would pass on it's own in a generation or so. None anticipated or even could have anticipated, King Cotton and how it changed views on slavery to the point where Stephens and the Confederacy considered it to be the very cornerstone of their "republic."
EMANCIPATION AND THE YOUNGER GENERATION
Thomas Jefferson To Edward Coles
Monticello, August 25, 1814
http://www.mtsu.edu/~lnelson/Jefferson-Slavery.html
DEAR SIR, -- Your favour of July 31, was duly received, and was read with peculiar pleasure. The sentiments breathed through the whole do honor to both the head and heart of the writer. Mine on the subject of slavery of negroes have long since been in possession of the public, and time has only served to give them stronger root. The love of justice and the love of country plead equally the cause of these people, and it is a moral reproach to us that they should have pleaded it so long in vain, and should have produced not a single effort, nay fear not much serious willingness to relieve them & ourselves from our present condition of moral & political reprobation.
From those of the former generation who were in the fulness of age when I came into public life, which was while our controversy with England was on paper only, I soon saw that nothing was to be hoped. Nursed and educated in the daily habit of seeing the degraded condition, both bodily and mental, of those unfortunate beings, not reflecting that that degradation was very much the work of themselves & their fathers, few minds have yet doubted but that they were as legitimate subjects of property as their horses and cattle. The quiet and monotonous course of colonial life has been disturbed by no alarm, and little reflection on the value of liberty. And when alarm was taken at an enterprize on their own, it was not easy to carry them to the whole length of the principles which they invoked for themselves.
In the first or second session of the Legislature after I became a member, drew to this subject the attention of Col. Bland, one of the oldest, ablest, & most respected members, and he undertook to move for certain moderate extensions of the protection of the laws to these people. I seconded his motion, and, as a younger member, was more spared in the debate; but he was denounced as an enemy of his country, & was treated with the grossest indecorum.
From an early stage of our revolution other & more distant duties were assigned to me, so that from that time till my return from Europe in 1789, and I may say till I returned to reside at home in 1809, I had little opportunity of knowing the progress of public sentiment here on this subject. I had always hoped that the younger generation receiving their early impressions after the flame of liberty had been kindled in every breast, & had become as it were the vital spirit of every American, that the generous temperament of youth, analogous to the motion of their blood, and above the suggestions of avarice, would have sympathized with oppression wherever found, and proved their love of liberty beyond their own share of it. But my intercourse with them, since my return has not been sufficient to ascertain that they had made towards this point the progress I had hoped.
Your solitary but welcome voice is the first which has brought this sound to my ear; and I have considered the general silence which prevails on this subject as indicating an apathy unfavorable to every hope. Yet the hour of emancipation is advancing, in the march of time. It will come; and whether brought on by the generous energy of our own minds; or by the bloody process of St Domingo, excited and conducted by the power of our present enemy, if once stationed permanently within our Country, and offering asylum & arms to the oppressed, is a leaf of our history not yet turned over.
As to the method by which this difficult work is to be effected, if permitted to be done by ourselves, I have seen no proposition so expedient on the whole, as that as emancipation of those born after a given day, and of their education and expatriation after a given age. This would give time for a gradual extinction of that species of labour & substitution of another, and lessen the severity of the shock which an operation so fundamental cannot fail to produce. For men probably of any color, but of this color we know, brought from their infancy without necessity for thought or forecast, are by their habits rendered as incapable as children of taking care of themselves, and are extinguished promptly wherever industry is necessary for raising young. In the mean time they are pests in society by their idleness, and the depredations to which this leads them. Their amalgamation with the other color produces a degradation to which no lover of his country, no lover of excellence in the human character can innocently consent.
I am sensible of the partialities with which you have looked towards me as the person who should undertake this salutary but arduous work. But this, my dear sir, is like bidding old Priam to buckle the armour of Hector "trementibus aequo humeris et inutile ferruncingi." No, have overlived the generation with which mutual labors & perils begat mutual confidence and influence. This enterprise is for the young; for those who can follow it up, and bear it through to its consummation.
It shall have all my prayers, & these are the only weapons of an old man. But in the mean time are you right in abandoning this property, and your country with it? I think not. My opinion has ever been that, until more can be done for them, we should endeavor, with those whom fortune has thrown on our hands, to feed and clothe them well, protect them from all ill usage, require such reasonable labor only as is performed voluntarily by freemen, & be led by no repugnancies to abdicate them, and our duties to them. The laws do not permit us to turn them loose, if that were for their good: and to commute them for other property is to commit them to those whose usage of them we cannot control.
I hope then, my dear sir, you will reconcile yourself to your country and its unfortunate condition; that you will not lessen its stock of sound disposition by withdrawing your portion from the mass. That, on the contrary you will come forward in the public councils, become the missionary of this doctrine truly christian; insinuate & inculcate it softly but steadily, through the medium of writing and conversation; associate others in your labors, and when the phalanx is formed, bring on and press the proposition perseveringly until its accomplishment. It is an encouraging observation that no good measure was ever proposed, which, if duly pursued, failed to prevail in the end.
We have proof of this in the history of the endeavors in the English parliament to suppress that very trade which brought this evil on us. And you will be supported by the religious precept, "be not weary in well-doing." That your success may be as speedy & complete, as it will be of honorable & immortal consolation to yourself, I shall as fervently and sincerely pray as I assure you of my great friendship and respect.