Pardon me for offering a history lesson on the Confederate Battle Flag and the reason it came into existence, the Civil War. Most wars are unnecessary and lead to "most of the troubles of the world" as spoken by Ashley Wilkes in Gone With the Wind and the Civil War is no exception.
The southern states-led by South Carolina-had no reason to secede. They had won the argument over slavery that had been growing since the Missouri Compromise of 1820. I would note the following:
1. The Compromise of 1850 gave the slave states freedom (I hate to use that word here) to bring slaves into an area once prohibited to slavery; that being New Mexico and Utah.
2. That 1850 compromise also gave the slave states a "more stringent Fugitive Slave Law", meaning escaped slaves in the north were required to be returned to their owners with the help of federal and state officials.
3. The Kansas-Nebraska Act of 1854 made the Compromise of 1820 null and void, or unconstitutional.
4. Then in 1857 the Supreme Court came out with the Dred Scott decision declaring that it was unconstitutional to ban slaves in the territories.
5. Up till the election of 1860 the Democratic Party controlled all three branches of government and had nearly done so for many years.
6. The Democratic candidate in 1860-Stephen Douglas- supported a plan to allow settlers of the new territories to decide for themselves the status of slavery in their territory. (He did advise on how that could be ignored, in order to win a Senate seat in Illinois).
7. If the southern democrats who supported John Breckinridge supported Douglas and those who supported John Bell (Union Party) had supported Douglas it is very possible Lincoln would have lost to Douglas and the democrats would have continued to hold the Presidency, giving South Carolina no reason to leave the Union.
8. The Supreme Court ruling (Dred Scott) meant that slavery was legal in all territories and only a constitutional amendment could have changed that, something not likely to occur with southern states still in the Union and voting.
9. With even the south's most dreaded opponent-Lincoln-the institution would have been guaranteed existence in the places where it all ready existed.
Back to the original question of what was the need of the south to secede. There was nothing left to argue, they had won them all. Hell, if anyone should have seceded it would have been the New England states (imagine how history would have changed if New England seceding and joining Canada and the western territories were up for grabs). I also wonder if the racial situation in this country could have been any worse fi the Civil War never happened.
The south wanted war-certainly South Carolina did-and the other ten states went along. And as classical literature once noted "you loose the dogs of war" and there is no controlling where they go.
You would think the south would want to down-play the decision that caused so much violence, death and destruction instead of remember their folly by waving the battle flag.