The argument of "Necessity" was the only argument they ever admitted in favor of slavery; and so far, and so far only as it carried them, did they ever go. They found the institution existing among us, which they could not help; and they cast blame upon the British King for having permitted its introduction. BEFORE the constitution, they prohibited its introduction into the north-western Territory---the only country we owned, then free from it. AT the framing and adoption of the constitution, they forbore to so much as mention the word "slave" or "slavery" in the whole instrument. In the provision for the recovery of fugitives, the slave is spoken of as a "PERSON HELD TO SERVICE OR LABOR." In that prohibiting the abolition of the African slave trade for twenty years, that trade is spoken of as "The migration or importation of such persons as any of the States NOW EXISTING, shall think proper to admit," &c. These are the only provisions alluding to slavery. Thus, the thing is hid away, in the constitution, just as an afflicted man hides away a wen or a cancer, which he dares not cut out at once, lest he bleed to death; with the promise, nevertheless, that the cutting may begin at the end of a given time. Less than this our fathers COULD not do; and NOW [MORE?] they WOULD not do. Necessity drove them so far, and farther, they would not go. But this is not all. The earliest Congress, under the constitution, took the same view of slavery. They hedged and hemmed it in to the narrowest limits of necessity.
In 1794, they prohibited an out-going slave-trade---that is, the taking of slaves FROM the United States to sell.
In 1798, they prohibited the bringing of slaves from Africa, INTO the Mississippi Territory---this territory then comprising what are now the States of Mississippi and Alabama. This was TEN YEARS before they had the authority to do the same thing as to the States existing at the adoption of the constitution.
In 1800 they prohibited AMERICAN CITIZENS from trading in slaves between foreign countries---as, for instance, from Africa to Brazil.
In 1803 they passed a law in aid of one or two State laws, in restraint of the internal slave trade.
In 1807, in apparent hot haste, they passed the law, nearly a year in advance to take effect the first day of 1808---the very first day the constitution would permit---prohibiting the African slave trade by heavy pecuniary and corporal penalties.
In 1820, finding these provisions ineffectual, they declared the trade piracy, and annexed to it, the extreme penalty of death. While all this was passing in the general government, five or six of the original slave States had adopted systems of gradual emancipation; and by which the institution was rapidly becoming extinct within these limits.
Thus we see, the plain unmistakable spirit of that age, towards slavery, was hostility to the PRINCIPLE, and toleration, ONLY BY NECESSITY.
In Lincoln's famous 1860 Cooper Union speech, he noted that of the 39 framers of the Constitution, 22 had voted on the question of banning slavery in the new territories. Twenty of the 22 voted to ban it, while another one of the Constitution's framers--George Washington--signed into law legislation enforcing the Northwest Ordinance that banned slavery in the Northwest Territories. At Cooper Union, Lincoln also quoted Thomas Jefferson, who had argued in favor of Virginia emancipation: "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...."
To be sure, the Founding Fathers weren't abolitionists. But they were overwhelmingly antislavery.
I eagerly await George Stephanopoulos's "fact check" of Honest Abe.