The correct answer is: Familiarity with and disdain for the Northern industrial workplace.
In the 1860s the Southern states based their economy on agriculture, their crops required lots of manpower so they relied on slavery to work on their harvest. The Northern states were beginning to base their economy on manufacture and factories and they relied mainly on immigrants to work on factories, and were in favor of the abolition of slavery.
So when Abraham Lincoln won the elections in 1860, the Southern states felt the government was in hands of the Northern states and that it no longer watched over the Southern interests, they saw with disdain the Northern activity and that became a reason for the Southern secession from the Union.
