First of all, the Civil War was not only about slavery; I've heard even left-leaning scholars argue that slavery was actually not the primary issue. In college I had an opportunity to study the history of the civil war in an advanced class normally open only to senior-year history majors, and the prof was known for being one of the most in-depth professors on campus. It was facinating, and eye opening.The one thing I'd appreciate a little more insight on is the confederate flag. I mean the reason they secede in the first place is because they wanted to keep their slaves. In my mind the flag was a symbol of the fight to continue slavery in the south. And many people I know feel the same way. Why not pick another flag to represent Southern pride that doesn't have a dark past?
The foremost issues causing the Civil War were economic, and revolved around foreign trade, and tariffs imposed by the Federal government (chiefly in response to New England intrest groups that wanted to curtail the South being able to trade directly with other nations, cutting into their shipping and manufacturing profits.) It became a central-authority vs States-rights political battle, that turned into civil war because the Northern-dominated legislature wasn't listening when the South told them "your tariffs are going to bankrupt us."
Slavery was actually a secondary issue to most people at the time. It was used as a "causus belli" or propaganda element... part of this was because of the actions and lobbying of various emancipation groups, but also party because it made excellent propaganda to characterize the war as a war of good vs evil.
It is axiomatic that the victors write the history books, and so after the war the "free the slaves" aspect was emphasized and the economic and Fed-vs-State issues were marginalized. Most people don't have a clue about the real causes anymore.
But... lots of Southerners are well educated on this subject and know that the war was far from being all about slavery.
Many of us see the Stars-and-Bars as a symbol of state sovereignty and rights, a symbol of resistance to tyranny, rather than anything to do with slavery per se.
I myself do not fly the Confederate flag, out of consideration to certain of my fellow Americans who are unaware of the factors explained above, but I support the right of any Southerner to do so, and I try to educate those who are unaware of its meaning to Southerners.