Also, my thoughts from earlier this week:
The Citrus culture won't develop beyond a local curiosity (like our vineyards) in a nation without the markets of the north, and thus neither will the railroads or the tourism industry that followed the railroads. So it'll be Salt, Sponges, Fish, and Cattle with Sugar as a possible main industry. But Cattle will be the dominant source of income when you get inland, and by a massive margin. This is good, as Cracker Cattle are damn near invincible, and delicious, even if they're small for cattle, and hilariously mean (I've seen one run down and
kill a Coyote just for the hell of it.)
Tampa will be the big port for the region, since it's the only real natural Deep water port between New Orleans and Jacksonville, and the Phosphate industry will be big sooner or later, as Bone Valley is a massive deposit of it, and easily accesible for much of the world. Someone will build a railroad connecting Tampa to the rest of the region eventually, probably following the old Military roads from the Seminole Wars, since the terrain's flat enough to do that.
Maybe the Tourism industry will take off there after all that's done, with people coming to visit the Beaches in West Hillsborough (Currently Pinellas County, and it'll need a good road or a railroad first between the two first given how long it took to go between Dunedin and Tampa back then,) and enjoying the springs.
IMO Someone will release monkeys to satisfy the few tourists, or just by misshandling a few crates at a port. They will soon range across the state.
Someone might try drilling off the coast, following the boom in the Western Gulf, and will probably strike oil sooner or later, and find a lot of it. (it's a near certainty that it's under there, but we all agreed that the Industry we have is more important than the Industry they want, also for the most part, we really don't want to be like Texas or Alabama.) The Cigar industry might be more inevitable (but I hate to use that word in this situation) if the Local Tobacco's good enough, and if the laws treat Cubans well enough.
There might not be any tale of Jose Gaspar ITTL, given the circumstances involved in the popularization of the legend, but who knows? Afterall, the man might have been real.
Key West will remain vital as a transshipment port, and will only become more important as Wrecker's base and a Coaling station, although still being held by the Union, along with Fort Jefferson. It's just too damn strategic, and they held it through the war, so they aren't just going to hand it over without a serious fight and naval blockade.
You might not see it attract any immigrants at all ITTL besides Cubans and Bahamians given how shitty the CSA was at attracting such. Still, expect some Cuban Planters to land in Miami or there abouts and try to drain the Everglades to get at the Precious, precious Muck, which is perfect for tropical crops, but they probably won't do to well, between the Seminoles, and any slaves (assuming they brought slave labor, or that it's CSA territory) escaping off to join the Seminoles.
On that note, Black Seminoles were and still are a thing even if they were never officially part of the tribe, and most got expelled to Oklahoma with the majority of the tribe, give me a bit, and I could find a few books on them. Still, from a few dozen to a few hundred Seminoles, you could easily have a couple thousand by the end of the 19th Century. That's about where they were IOTL anyway. The Numbers of official members are always somewhat problematic, given the issue of defining such. It's very much like trying to count Jews, with all the attendant issues.
As for Animals, well, the Ivory billed Woodpecker ought to be only endangered ITTL, since the singer tract up north will likely go unused, along with much of the Suwannee river basin, although paradoxically, the Choctawhatchee River might see more logging. The Carolina Parakeet OTOH should be fine, since Cockleburrs will be
everywhere, and while there might not be alot of Farming in North Florida it might not extend as far south, or be as dense, so they could range a bit further and might not get utterly fucked over by Poultry Disease like OTL.
The Everglades won't be as much of a disaster either, with fewer imported species, and the most important industries down there just being Seminoles hunting Gators and Birds for skins and feathers to satisfy the demand among more the Upper classes.
Sandhill cranes, gopher turtles and Burrowing owls ought to be well off as well, since development is what did them in. Hopefully however, no-one introduces Starlings. They'll drive everything else out.
In short, Florida will be a mix of wasted potential and industry, with fewer white folks, and a whole region where it just isn't safe to have that twang in your voice, but still, places will be recognizable. After all, it's Florida, the weird State that is completely it's own place. And without Phosphates, Oil or the Keys, no-one really wants the place.
With a completely different culture, likely a different Language (be it Spanish, Seminole, or an offshoot of Bahamian Creole) and certainly a completely different History, South Florida, (and after a while possibly even parts of North Florida,) will be rather nationalist, and independence-minded, given that they will naturally look south and outward instead of to their north for business and their interests.
Also, some other stuff on Florida that might prove immediately useful:
USGS Map of Coal deposits.
Defining the differences and separation of North And South, with a decent amount of discussion on the Florida Problem.