I agree that TTL will have created even more separate and distinct cultures of people than what occurred in OTL. But in the United States of TTL, an entire generation has come of age since slavery was abolished throughout the country.
This is true. On the other hand, people in the US haven't had to choose a side on the issue since it isn't in the US. I think what this means is that the whole of US public opinion ITTL is shifted closer to the abolitionist side than OTL, but that means that there are still plenty of Americans in the ambiguous center (we don't do that here, but when in Rome....).
Add to that the general animosity and competition that Americans (US citizens) will have with British Americans,
And this would be similar to OTL America's burning animosity towards
Canadians?
Or those vile slaving Jamaicans!
Truth is, the Federalist/Pro-British faction has actually been stronger ITTL than in OTL, and the Accord of 1804 has done a lot to calm tensions between the two regions (though not all). While the British South is seen in some quarters as evil for their slaving ways, and in some as competition (mostly in the west), most Americans see them as trade partners. Southern Cotton isn't just going to British textile plants, but also to American ones.
and how much different they will see each other,
Most Americans see Southerners as Royalty loving, nobility-aping pseudo-Virginians. Most Southerners see Americans as godless (or papist) radical Yankees who worship the almighty buck, except those Frenchies up north and those pseudo-Southern Viriginians who aren't that bad.
I would expect to see those same attitudes and feelings come out in the empresarios
Maybe, but by their very nature they are a bit of an odd bunch.
and settlers who came to Texas from both the US and BSA.
Much more so here, though, you're right.
I just think there will be much less ambivalence on the part of Americans toward slavery than what Northerners felt toward it in OTL.
Human nature being what it is, I actually disagree. You will get more Northerners ITTL to knee-jerk agree with the statement that slavery is wrong. However, if you could rate their level of passion about the issue, it would be less so because
it's not their problem. Now then, if someone were to come along and try to get slavery legalized in the US, that would be a dead issue and the proposer would likely get beaten up for his trouble, but as long as them British Southerners keep South of the 36-30, they're not going to go out of their way about it (except TTL's version of the Underground Railroad....).
Furthermore settlers from BSA will feel more British, more loyal, more superior, more civilized, I think, to the Americans who they would see as low bred, traitors,
The ones who come from the slaveocracy, yep.
and general no goods. And when you mix these groups in Texas,
However, not all the settlers coming from the British South are from the slavocrats. A lot of them are poor whites looking to set up independent claims, and trying to get away from the stiffling plantation system. They are pretty loyal to the crown, but not necessarily to the plantation system.
I think yoo will end up with something like a Bosnia.
I mentioned somewhat that
if a Texas Civil War occurs, it would be more like that, yes.
But its your TL so I won't try to change anything, just giving you something to think about.
Indeed you have. Much of it I had already thought of, and I won't say that your interpretation of how things would go is wrong, just that things took a slightly different tack ITTL.