By Abraham Lincoln
From a speech, Peoria, Illinois :
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... 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.
[HT: John McCormack @ The Weekly Standard.]