basically what the Tin says, say the CSA wins early in the war, say September 1862, they take DC and force peace, any ways, what would Slavery look like after the war? how long would it last? and how would it end?
Initially, the CSA would be the The South Triumphant, with slavery as its proud banner.
That wouldn't last. It would alienate opinion in Europe, and create permanent disgust for the CSA in the USA.
The CSA would have a lot of difficulties. Independence would not repair the economic damage of the war, and cotton prices would remain depressed.
The "Fire-Eater" claims that with victory, everything will be wonderful would fade out. There would be bitter divisions over who was to blame for the problems and what to do about them.
Lower class whites would find that the planter elite ruled to suit itself.
By the 1870s, these problems would be acute, and would be greatly aggravated by the CSA's ugly image abroad.
Another factor is that with white supremacy wired into the CSA constitution, paranoia about abolitionists starting slave rebellions would fade.
Eventually, some Southerners would begin to argue that formal chattel slavery was not really needed. The blacks could be converted to indentured servants, and nothing really need change. The PR benefits would be huge - and would be badly needed.
Some kind of preference cascade would happen, and the formal abolition of slavery would take place around 1882.
Alternately - the slaveholder elite digs in hard, and suppresses any questioning of slavery. The CSA becomes an impoverished pariah state, whose ruling class clings fanatically to the fantasy of the Old South.
The white lower class becomes increasingly alienated; the black slaves increasingly restive.
This lasts until a bit after 1900, when there is a cultural and political upheaval throughout the South, and the entire slavery system and its political basis are tossed out. There are simultaneous revolutions by poor whites in the Upper South and blacks in the Deep South against their common enemy. When the smoke clears, the blacks have established a series of enclaves where slaves were most concentrated. The new white governments recognize the enclaves as independent. Blacks in other areas are mostly shipped off to the Colored Reserves.