You know, the one that would have made slavery legal nationally? I refer to the slavery amendment that Lincoln urged governors to adopt in March, 1861?
ART. 13. 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.Well the fourth of many Lincoln letters urging the adoption of the national slavery amendment was discovered in Allentown recently.
No big deal though. As usual, it was (somehow) all Buchanan's fault.