"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.
U.S., Statutes at Large, Treaties, and Proclamations of the United States of America, vol. 12 (Boston, 1863), p. 251.