OOC: Sure, why not? The cultural blend might prove interesting, to say the least.
OOC: I picture Carolina as sort of like the New Orleans culture writ-large (and without the French influence, Spanish takes its place). Of course, it and Virginia both encompass what would in OTL be considered "Southron" characteristics, just in different ways. I figure Virginia is more "baseline" due to influences from Ohio, Pennsylvania and Maryland, but still not "Northern" like NY or Michigan either. The race relations issue you mention would be proof of that (and in many ways, it'd probably make Virginia more recognizable to an OTL Alabamian or Georgian than much of Carolina would

). However, there's also the Neo-Classicist attitude prevalent as well, which would be in line with an earlier emancipation. And let us not forget the more successful Drake influencing the country as a national hero
IC: At least the one good thing that managed to come out of the Spanish system's influence on Carolinian society was that blacks had an easier time assimilating once slavery ended down there in the late 1860s.....here in Virginia, slavery began to end earlier(the late 1840s, around the same time as in Tejas), but assimilation was much harder for the first fifty years or so; race riots were a problem, particularly in the heady days of the 1880s(nobody in Victoria City will ever forget the day that the Midtown Massacre happened in November, 1884; there's a reason many of African descent still fear the names of Hugh Thomas Griffin and William C. Featherston to this day.). Though, thankfully, at least things began to improve around the turn of the century and we've had no problems since the 1950s, particularly thanks to black soldiers participating in the World War.
IC: Well, a lot of the difference in race relations between the sister republics had to do with how they viewed their respective black populations. Virginia may have considered itself the more "Enlightened" of the two, and genuinely wished deep down to end forced bondage, but at the end of the day most Virginians back then either considered blacks as subhuman entirely, or at best were apathetic (and the latter was less common than you'd think). Carolinians, on the other hand, may have been far more invested in slavery and agrarianism, but they also saw their slaves from Africa as human beings; granted, they considered them a "subject race" that couldn't be left to its own designs in good conscience, but they still saw them as people and not chattel. And of course, the idea of a race riot wouldn't have gone down well in either country, it's just a matter of that difference in treatment producing more radical results.
Of course, that's all irrelevant now since both countries have full equal rights and racism is on the down-swing; sharing a foxhole with a man you can trust with your life does wonders to end stupidity like that.
OOC: Victoria City is on the site of OTL's Lynchburg and has a size comparable to Toledo, OH in the 1970s or Bakersfield, CA today; or, more precisely, roughly 380k inhabitants, at least 4x larger than Lynchburg.
My idea for the World War could be best described as like a mix of WWI and WWII in many ways(just without any equivalent to the Nazis), with bits of other conflicts thrown in, and lasted from November 1928 to September 1935.
OOC: Fair enough. I figured other important cities in VA may be Williamsburg (the pre-Bacon capital, which may still be the capital unless it gets moved up to OTL D.C.s location, which is more centralized in relation to Maryland, the Delmarva and the Alleghany chunks in OTL Ohio and PA), Baltimore, Lexington (different name?), Pittsburg (ATL Pittsburgh), Petersburg (OTL Richmond) and Hampton. The World War would be interesting, albeit a good deal bloodier likely than WWI. Also, Featherston?
IC: Getting back to the topic at hand, one consequence of the English conquest, from a linguistic and cultural perspective, is the survival of "Castillian" identity in New Granada and parts of Cuba, and the retention of un-Anglicized Spanish traditions such as bullfighting and old-school guitar playing. Plus they speak a relatively "pure" Spanish set of dialects in the Americas, whilst Spain obviously speaks a sorta creole thanks to the heavy English influence the conquest left behind.