I haven't tried to turn this into a debate over the causes of the Civil War. I'm well aware of your views there and have no interest in trying to persuade you otherwise. (And for the record, I do think that the South would have abolished slavery eventually.)
If I have mistaken your intentions, I do apologize.
I have already offered several points along those lines, but I've yet to see you respond to them. Where the best cotton land is in Mexico, for instance, or an easy way to organise funding for a transcontinental railroad ahead of OTL (a copper boom in Sonora), or the best way for the USA to hold down Mexico (get the big landowners onside and keep 'em that way).
If you want another one, the method you picked to abolish slavery, as per version 2.0 of the timeline, has some problems as it stands, but could be modified slightly to work.
Slave prices are only going to rise as high as someone's willing to pay, which means enough to turn a profit from the most profitable crop. (Mostly cotton, with sisal in Yucatan if that area's pacified). But this will mean more concentration of slave labour in those areas which grow cotton, and reduced support for slavery elsewhere. (Since they have few slaves around, most of them having moved to the cotton belt.) From Durango to Alabama, there's cotton slaves at high prices (but still turning a profit.) The Upper South and whichever parts of Mexico get held onto would be likely to turn into free-soil states. With Durango-Coahuila to move into, even Florida may be seen as unprofitable for the most part for slave agriculture, and so that could end up as a free soil state too. Having so many free soil states around would make it a lot easier to push the abolition of slavery through later.
I can see your point that this would be a viable mechanism for the elimination of slavery in the U.S.A. I had wanted to avoid having a lot of "free soil" states arise prior to the collapse of the cotton markets and the breakup of the plantations, because then we are simply replicating what happened in the old Union and we quite possibly end up with a Civil War within the U.S.A. However, I will consider your suggestion and may incorporate it in a revision later.
One factor which your reply did bring to mind was this...you mention the very valid point that the price of slaves is only going to go as high as someone's willing to pay. However, there is the possibility that we might gradually see the small and medium-scale slaveholder priced out of the market, with only the richest men able to afford slaves. This in turn, might, over time, actually lead to the breaking of the power of the plantation class over U.S. politics. In OTL, non-slaveholders in the South often supported slavery because they envisioned a time when they might become slaveholders themselves. Therefore they allied themselves with the planters and their political agenda. The prices of slaves by 1860 in OTL were already making it a real challenge for entry-level prospective slaveowners to enter the market. Push those prices up a bit higher, and it becomes virtually prohibitive. As gradually the realization sinks in to the average non-slaveowning Southerner that he has no chance of ever entering the slaveowning aristocracy, might we not see more Hinton Helpers arise among the non-slaveowning majority in the South, and an erosion of support for the political agenda of the aristocracy?
I have been thinking about another factor that might go along with this...conflict between Anglophones vs. Spanish-speakers. As more Mexicans move north to work in the growing industrial cities, and Mexicans become the largest and most threatening ethnic minority (possibly, given high birthrates in Catholic families, even a majority over time), might it not be possible that English speaking whites might be gradually drawn to view the other large group of English speakers in the U.S.A....blacks...as less of a threat and a possible ally against the "Mexican menace?" If that happened, there might be increasing pressure in some quarters for the abolition of slavery and the extension of political rights to the former slaves. Of course, then they would have to either extend political rights to the Mexicans, or redefine citizenship in a way as to include blacks but exclude Mexicans.
Personally, I'd welcome constructive criticism of Decades of Darkness if you want to do so. I've modified the timeline in the past based on people's input, and no doubt will do so again. That doesn't mean that I'll automatically change things (there's a lot of research gone into working things out, and there's reasons why most things in there happen as they do) but I do listen.
Decades of Darkness is such a large and detailed work at this point that any modifications you made to the earlier portions of the timeline would necessitate a re-write of most of it. If it were still at an early stage, I'd consider taking up your offer. As it is, it's probably not a good idea. But you have mentioned that you are finishing up DoD and will be moving on to something else in the near future. Perhaps I will make myself a gadfly there.
