and walter edgar is a professor of history and southern studies at the university of south carolina. thank you all three. we appreciate your being with us. i just want to quickly share with our audience two findings from a poll that was done this month by the pew research center. when people were asked their reaction to seeing the confederate flag displayed 9% said they had a positive reaction. 30% a negative. and 58% said neither. and when people were asked what do they think the main cause of the civil war is, 48% said mainly about states' rights. only 38% said mainly about slavery. 9% said both. to each of you, what do historians think was the cause of the civil war and what do you think? >> well, historians are pretty united on the cause of the civil war being slavery. and the kind of research that historians have undertaken especially in the years since the centennial when there has been so much interest in this question of the role of race and slavery in the united states, that research has shown pretty decisively that when the various states announced their plans for secession