Following the victory of Abraham Lincoln in the election of 1860, the secession of Southern slaveholding states seemed inevitable. The most important effort during the interval between Lincoln's election and inauguration to prevent this outcome was a series of constitutional amendments proposed by Senator J.J. Crittenden of Kentucky on December 18, 1860.
Crittenden sought to allay the fears of the South by enacting into the constitution certain guarantees of regarding slavery in America. He proposed that line drawn in the Missouri Compromise of 1820 be extended to the Pacific and that while slavery would be prohibited north of it, the property rights of slaveowners would be guaranteed south of it.
The compromise was defeated on December 22 when Republicans, acting under the advice of president-elect Lincoln, refused to compromise on the question of slavery in the territories. Southerners pointed to this unwillingness to compromise as proof that the South had no choice except to secede.
The resolution for an amendment to prohibit interference with slavery in the states was passed by Congress in February and March, 1861, but was never ratified by the states.