Slavery would start collapsing anytime from 1880 onward at earliest, after the abolishment of slavery in Brazil the CSA will be left with no one but themselves defending slavery as a institution on the international stage, both Britain and France by the 1880's will have successfully started growing cotton in their colonies and see less reason to deal with them as confederate cotton will be seen as "unethical competition" to "ethical British and French enterprise"
Except that the perpetuation of slavery by the Confederacy may bolster the rightest elements in Brazil, and perpetuate it there too.
[quote[This coupled with the Boil Weevil arriving in the 1990's as well as the CSA's political troubles and the constant economic shocks of the gilded age from industrialization will either cause the CSA to collapse into infighting or have a national crisis which will force the government to allow the states to use their "right's" to decide their own future.[/quote]
I think you mean 1890's, but regardless, the Boll Weevil took thirty or forty years to spread all the way through the south. It's not like 1896, the Boll Weevil shows up, and 1897, the entire cotton crop is gone. It's far more gradual.
In any case if any of the Confederate States try to leave they might ironically try to region the union if it means a end to the chaos....
Confederate Constitution explicitly forbade further secession.
However slaver will cease to exist by 1910 at latest I have seen quite a few TL's on here that think it could survive up until the 1930's but there is in my opinion, no realistic way it could survive that long, anything after 1910 is, in my opinion ASB
I'd say, at least to the 1920's, and quite possibly much later. Assuming they just take the name off and call it something else, then well into the 50's and 60's.