Census of 1860 data is striking. Slave population % of the seceding states was huge, much larger than border slaves states - also, the free black population was tiny everywhere but a handful of places. Just 1.2% of the population of the free states & territories. 
One of the cruel ironies of secession over slavery - and yes, secession was about slavery - is that slaveholders were themselves a small % of the population. In Virginia, 4.7% were slaveholders; 3.6% were free black Americans.
For all the size of the economic footprint of slavery, it was outside the lived experience of most Americans by 1860: <400,000 slaveholders in a nation of 31 million. And most of those held 5 or fewer slaves. Yet they drove the nation to war.
The mismatch between the small size of the slaveholding population & the vast number of people held in bondage never ceases to be shocking. Numbers don't tell the whole story, of course, but they speak volumes of their own.
Then there's this map of slavery's geographic distribution. Lincoln loved this map so much, the famous portrait of him & his Cabinet on the signing of the Emancipation Proclamation shows the map propped by a chair.
More on the mapping of freedom & slavery here: mappingthenation.com/index.php/chap…
The Confederacy has been commemorated for many reasons, not all of them bad. What needs to end is not all memory of gallant Southern soldiery & whatnot, but the downplaying of what the Confederate cause actually stood for. The best remedy for that is unblinking truth.
The hard truth of the Confederacy is that nearly 4 in 10 of its people lived in chains, in service of a tenth of their number, and everybody knew it.
The typical Confederate soldier fought for hearth, home, & honor, not for slavery. But he fought in slavery's cause under slavery's flag.
The sons, daughters, & grandchildren of such men sought to honor them, for human reasons anyone can understand. Those sons, daughters, & grandchildren should be judged, not for remembering, but for forgetting - & for what they did with their own times.
We, the living, have the same duty: tell the truth about the past, & do justice in the present.
