"I understand a proposed amendment to the Constitution—which amendment, however, I have not seen—has passed Congress, to the effect that the Federal Government shall never interfere with the domestic institutions of the States, including that of persons held to service. To avoid misconstruction of what I have said, I depart from my purpose not to speak of particular amendments so far as to say that, holding such a provision to now be implied constitutional law, I have no objection to its being made express and irrevocable." - Abraham Lincoln speaking a the Inauguration of the 16th President of the United States, March 4, 1861
The amendment about which he was speaking that had been passed by an all yankee congress (the southern senators and representatives had almost entirely left washington by that time) only two days earlier....
"Article Thirteen. "No amendment shall be made to the Constitution which will authorize or give to Congress the power to abolish or interfere, within any State, with the domestic institutions thereof, including that of persons held to labor or service by the laws of said State."
APPROVED, March 2, 1861. Source: U.S., Statutes at Large, Treaties, and Proclamations of the United States of America, vol. 12 (Boston, 1863), p. 251.
"I will say then that I am not, nor ever have been, in favor of bringing about in any way the social and political equality of the white and black races - that I am not, nor ever have been, in favor of making voters or jurors of Negroes, nor of qualifying them to hold office, nor to intermarry with white people; and I will say in addition to this that there is a physical difference between the white and black races which I believe will forever forbid the two races living together on terms of social and political equality. And inasmuch as they cannot so live, while they do remain together there must be the position of superior and inferior, and I as much as any other man am in favor of having the superior position assigned to the white race." - Lincoln, 8/17/1858.
"You and we are different races. We have between us a broader difference than exists between almost any other two races. Whether it is right or wrong I need not discuss, but this physical difference is a great disadvantage to us both, as I think your race suffer very greatly, many of them by living among us, while ours suffer from your presence.... It is better for us both, therefore, to be separated." - Lincoln, speaking to a group of former slaves 8/1862