Here's one take on it. As is usual with with wars it was about wealth and power.
http://www.swcivilwar.com/cw_causes.html
At the Constitutional Convention there were arguments over slavery. Representatives of the Northern states claimed that if the Southern slaves were mere property, then they should not be counted toward voting representation in Congress. Southerners, placed in the difficult position of trying to argue, at least in this case, that the slaves were human beings, eventually came to accept the three-fifths compromise, by which five slaves counted as three free men toward that representation. By the end of the convention the institution of slavery itself, though never specifically mentioned, was well protected within the body of the Constitution.
It seemed to Thomas Jefferson and many others that slavery was on its way out, doomed to die a natural death. It was becoming increasingly expensive to keep slaves in the agrarian society of the south. Northern and Southern members of Congress voted together to abolish the importation of slaves from overseas in 1808, but the domestic slave trade continued to flourish. The invention of the cotton gin made the cultivation of cotton on large plantations using slave labor a profitable enterprise in the deep South. The slave became an ever more important element of the southern economy, and so the debate about slavery, for the southerner, gradually evolved into an economically based question of money and power, and ceased to be a theoretical or ideological issue at all. It became an institution that southerners felt bound to protect.
I don't know how Southerners came to be perceived so backward, perhaps it's a leftover from reconstruction when the North was industrializing and in a boom while the South remained agrarian and largely poor. My high school history never said much about that time. The idea was certainly capitalized on by popular writers in mid twentieth century from Al Capp to Tennessee Williams, to the extent many believe it.
That the Confederate Flag somehow represents hatred or anger or something racial is IMHO a reflection from the eye of the beholder. It's just an artifact from a nation that existed briefly during a tumultous time.
But the fact remains we Americans are fascinated with our lineage, and anyone who is belittled on account of his ancestry is likely to wave that ancestor's flag back in your face and invite you to step outside.
a.
Cogito ergo doleo.
