Sorry for the length, this is from the Cooper Union speech:
"But enough! Let all who believe that "our fathers, who framed the Government under which we live, understood this question just as well, and even better, than we do now," speak as they spoke, and act as they acted upon it. This is all Republicans ask - all Republicans desire - in relation to slavery. As those fathers marked it, so let it be again marked, as an evil not to be extended, but to be tolerated and protected only because of and so far as its actual presence among us makes that toleration and protection a necessity. Let all the guarantees those fathers gave it, be, not grudgingly, but fully and fairly, maintained. For this Republicans contend, and with this, so far as I know or believe, they will be content.

And now, if they would listen - as I suppose they will not - I would address a few words to the Southern people.

I would say to them: - You consider yourselves a reasonable and a just people; and I consider that in the general qualities of reason and justice you are not inferior to any other people. Still, when you speak of us Republicans, you do so only to denounce us a reptiles, or, at the best, as no better than outlaws. You will grant a hearing to pirates or murderers, but nothing like it to "Black Republicans." In all your contentions with one another, each of you deems an unconditional condemnation of "Black Republicanism" as the first thing to be attended to. Indeed, such condemnation of us seems to be an indispensable prerequisite - license, so to speak - among you to be admitted or permitted to speak at all. Now, can you, or not, be prevailed upon to pause and to consider whether this is quite just to us, or even to yourselves? Bring forward your charges and specifications, and then be patient long enough to hear us deny or justify.

You say we are sectional. We deny it. That makes an issue; and the burden of proof is upon you. You produce your proof; and what is it? Why, that our party has no existence in your section - gets no votes in your section. The fact is substantially true; but does it prove the issue? If it does, then in case we should, without change of principle, begin to get votes in your section, we should thereby cease to be sectional. You cannot escape this conclusion; and yet, are you willing to abide by it? If you are, you will probably soon find that we have ceased to be sectional, for we shall get votes in your section this very year. You will then begin to discover, as the truth plainly is, that your proof does not touch the issue. The fact that we get no votes in your section, is a fact of your making, and not of ours. And if there be fault in that fact, that fault is primarily yours, and remains until you show that we repel you by some wrong principle or practice. If we do repel you by any wrong principle or practice, the fault is ours; but this brings you to where you ought to have started - to a discussion of the right or wrong of our principle. If our principle, put in practice, would wrong your section for the benefit of ours, or for any other object, then our principle, and we with it, are sectional, and are justly opposed and denounced as such. Meet us, then, on the question of whether our principle, put in practice, would wrong your section; and so meet it as if it were possible that something may be said on our side. Do you accept the challenge? No! Then you really believe that the principle which "our fathers who framed the Government under which we live" thought so clearly right as to adopt it, and indorse it again and again, upon their official oaths, is in fact so clearly wrong as to demand your condemnation without a moment's consideration.

Some of you delight to flaunt in our faces the warning against sectional parties given by Washington in his Farewell Address. Less than eight years before Washington gave that warning, he had, as President of the United States, approved and signed an act of Congress, enforcing the prohibition of slavery in the Northwestern Territory, which act embodied the policy of the Government upon that subject up to and at the very moment he penned that warning; and about one year after he penned it, he wrote LaFayette that he considered that prohibition a wise measure, expressing in the same connection his hope that we should at some time have a confederacy of free States.

Bearing this in mind, and seeing that sectionalism has since arisen upon this same subject, is that warning a weapon in your hands against us, or in our hands against you? Could Washington himself speak, would he cast the blame of that sectionalism upon us, who sustain his policy, or upon you who repudiate it? We respect that warning of Washington, and we commend it to you, together with his example pointing to the right application of it."
"Republican doctrines and declarations are accompanied with a continual protest against any interference whatever with your slaves, or with you about your slaves. Surely, this does not encourage them to revolt. True, we do, in common with "our fathers, who framed the Government under which we live," declare our belief that slavery is wrong..."
"In the language of Mr. Jefferson, uttered many years ago, "It is still in our power to direct the process of emancipation, and deportation, peaceably, and in such slow degrees, as that the evil will wear off insensibly; and their places be, pari passu, filled up by free white laborers. If, on the contrary, it is left to force itself on, human nature must shudder at the prospect held up."

Mr. Jefferson did not mean to say, nor do I, that the power of emancipation is in the Federal Government. He spoke of Virginia; and, as to the power of emancipation, I speak of the slaveholding States only. The Federal Government, however, as we insist, has the power of restraining the extension of the institution - the power to insure that a slave insurrection shall never occur on any American soil which is now free from slavery."
"But you will break up the Union rather than submit to a denial of your Constitutional rights.

That has a somewhat reckless sound; but it would be palliated, if not fully justified, were we proposing, by the mere force of numbers, to deprive you of some right, plainly written down in the Constitution. But we are proposing no such thing.

When you make these declarations, you have a specific and well-understood allusion to an assumed Constitutional right of yours, to take slaves into the federal territories, and to hold them there as property. But no such right is specifically written in the Constitution. That instrument is literally silent about any such right. We, on the contrary, deny that such a right has any existence in the Constitution, even by implication.

Your purpose, then, plainly stated, is that you will destroy the Government, unless you be allowed to construe and enforce the Constitution as you please, on all points in dispute between you and us. You will rule or ruin in all events.

This, plainly stated, is your language. Perhaps you will say the Supreme Court has decided the disputed Constitutional question in your favor. Not quite so. But waiving the lawyer's distinction between dictum and decision, the Court have decided the question for you in a sort of way. The Court have substantially said, it is your Constitutional right to take slaves into the federal territories, and to hold them there as property. When I say the decision was made in a sort of way, I mean it was made in a divided Court, by a bare majority of the Judges, and they not quite agreeing with one another in the reasons for making it; that it is so made as that its avowed supporters disagree with one another about its meaning, and that it was mainly based upon a mistaken statement of fact - the statement in the opinion that "the right of property in a slave is distinctly and expressly affirmed in the Constitution."

An inspection of the Constitution will show that the right of property in a slave is not "distinctly and expressly affirmed" in it."

"A few words now to Republicans. It is exceedingly desirable that all parts of this great Confederacy shall be at peace, and in harmony, one with another. Let us Republicans do our part to have it so. Even though much provoked, let us do nothing through passion and ill temper. Even though the southern people will not so much as listen to us, let us calmly consider their demands, and yield to them if, in our deliberate view of our duty, we possibly can. Judging by all they say and do, and by the subject and nature of their controversy with us, let us determine, if we can, what will satisfy them.

Will they be satisfied if the Territories be unconditionally surrendered to them? We know they will not. In all their present complaints against us, the Territories are scarcely mentioned. Invasions and insurrections are the rage now. Will it satisfy them, if, in the future, we have nothing to do with invasions and insurrections? We know it will not. We so know, because we know we never had anything to do with invasions and insurrections; and yet this total abstaining does not exempt us from the charge and the denunciation.

The question recurs, what will satisfy them? Simply this: We must not only let them alone, but we must somehow, convince them that we do let them alone. This, we know by experience, is no easy task. We have been so trying to convince them from the very beginning of our organization, but with no success. In all our platforms and speeches we have constantly protested our purpose to let them alone; but this has had no tendency to convince them. Alike unavailing to convince them, is the fact that they have never detected a man of us in any attempt to disturb them.

These natural, and apparently adequate means all failing, what will convince them? This, and this only: cease to call slavery wrong, and join them in calling it right. And this must be done thoroughly - done in acts as well as in words. Silence will not be tolerated - we must place ourselves avowedly with them. Senator Douglas' new sedition law must be enacted and enforced, suppressing all declarations that slavery is wrong, whether made in politics, in presses, in pulpits, or in private. We must arrest and return their fugitive slaves with greedy pleasure. We must pull down our Free State constitutions. The whole atmosphere must be disinfected from all taint of opposition to slavery, before they will cease to believe that all their troubles proceed from us.

I am quite aware they do not state their case precisely in this way. Most of them would probably say to us, "Let us alone, do nothing to us, and say what you please about slavery." But we do let them alone - have never disturbed them - so that, after all, it is what we say, which dissatisfies them. They will continue to accuse us of doing, until we cease saying.

I am also aware they have not, as yet, in terms, demanded the overthrow of our Free-State Constitutions. Yet those Constitutions declare the wrong of slavery, with more solemn emphasis, than do all other sayings against it; and when all these other sayings shall have been silenced, the overthrow of these Constitutions will be demanded, and nothing be left to resist the demand. It is nothing to the contrary, that they do not demand the whole of this just now. Demanding what they do, and for the reason they do, they can voluntarily stop nowhere short of this consummation. Holding, as they do, that slavery is morally right, and socially elevating, they cannot cease to demand a full national recognition of it, as a legal right, and a social blessing."

Again, this was from before Lincoln was nominated as the Republican candidate for president.