Comment: I moved around growing up and was in southern and northern schools with diverse viewpoints.  The issue was more complex than just slavery.  However, any compromise acceptable to the south would have continued slavery.  Also, while the call for ending slavery was growing, there wasn't the political will to make it happen.  Lincoln wasn't planning on pushing for ending slavery.  The biggest slavery related issues revolved around new states admitted to the union.  The chance for any compromise ended when the south rebelled. The south is not only responsible for a civil war and huge death toll, they are responsible for the inability to compromise.

Really, the only moral defense they have is the question of whether or not a state should be able to withdraw from the country.