There is a basic primal instinct somewhere hidden here that even before there was any fighting, as in 1860 and before, that men felt the need to defend something. And that basic instinct drove them to take the actions that they did. We are taught that this something was the institution of slavery, but I don't believe that, because men do not fight with such dedication to something they do not fully believe in and are not wholely commited to.
For Example our army today is a volunteer army. Do our soldiers, in our army today, fight because they are told to? Or do they fight because they live in the United States? Do they fight to protect their families? Or do they fight because they believe in something other than these United States, some idealogy?
The truth is that they will fight for all of those reasons, but which is the strongest incentive?
How many of them do you think fight for the United States Government and the President? Or for Bill Gates to own a Cadillac? No, you don't volunteer and put your life on the battle line for such silly things. You sell your life for dearer things than that.
I can understand the Northern Soldier fighting to "Preserve the Union" to preserve the Status Quo, like England in 1776. But, I can also understand the Southern soldier, and my Grandfathers, fighting for "Independence" like the 13 colonies.