Now, I worked out some math regarding 10,000-culture cities. At a rough estimate, building a temple at 250 AD, the other four basic buildings at 750 AD (to get the 1000-year bonus at the time slowdown at 1750 AD), and the research lab sometime later, adds up to about 8,500 culture before 2050 AD. I'm not sure how much of that Sirian knew, but 10,000 culture is an interesting goal to shoot for. By spreading out the wonders; I might be able to get as many as eight or ten cities above 10,000 culture.
Montreal and Toronto are already locks for 10k culture, with ancient wonders. Ottawa with any medieval wonder and the palace should be too. Hamilton, Vancouver (with the FP) and Edmonton have started prebuilding for wonders, and then will need the basic buildings rushed. Now, I started rushing the cultural buildings in the cities of Halifax, Oshawa, Quebec, and Winnipeg.
Building continued apace. The Great Library delivered me the technologies, and I spent the cash on cultural buildings. Surprisingly, no more tribute demands were coming in. I'd built a fair number of units to defend the border cities - a defender or two and then horsemen ready to upgrade if necessary - which apparently was enough military that nobody threatened me. Might I go all the way without a Blood Enemy?
In 570 AD, I got a pop-up that America was the Largest Nation in the World, although I'm still only 3rd in land area. Apparently that list is based on population?
Well, the wonder dominoes started falling. After the Great Library delivered Education, I researched Music Theory myself (in 5 turns), to trade for other techs and get another wonder prebuild in play. Music Theory came in just in time to let me swap my Sun Tzu's build over to Bach's, in Ottawa. I wanted the Sistine Chapel, but the AIs had too much of a head start after getting Feudalism earlier for any of my cities to reach 600 shields.
Only Babylon got to cascade to Copernicus, but it's due in that city (a backwater size-6 that must've been building forever) in 12 turns (780 AD.) My only city that could take it soon enough was Edmonton, which is a fairly low-trade inland city. But I can hardly worry about wasting a small percentage of Copernicus on THIS map. 
Maybe one day I'll stop getting surprised by this:
I'll certainly take it, though. That would let me finish building all my regular cultural buildings, finish Bach's ahead of any more cascading, research Navigation and Economics, and wrap up all the rest of the wonders. I actually set up an Excel spreadsheet to let me work out the best placement of the wonders. I targeted each city for about 10,500 culture and used a conservative date of 1750 for the research labs, to allow margin of error in case of rioting later.
It turned out that even mediocre Magellan's Voyage, built in 830 AD, would be enough to carry that city to 10k culture. Getting in those 1000-year doublings before the late-game time slowdowns gets a lot of culture later on.
I paused a moment over the question of whether to revolt to Democracy. I could take a few turns of anarchy after the Golden Age without trouble, and I could work out the 10k culture builds to allow for it. And the faster workers, lower corruption, and peripherals like higher flip chance would pay off significantly over the next 300 turns. But, what makes me decide not to is the high chance of getting forced into another round of anarchy by late-game war weariness - that's too likely to happen in the vast gulf of time before 2050 AD.
Babylon made things interesting:
It'll be a phony war for now, since I have no intention of making any attack on the other continent before airports (it takes 12 turns to sail to Babylon from here!), but at least it gives me an eligible candidate for Blood Enemy, finally.
If anyone still doubts the AIs cheat with regard to map knowledge, check this out. I made some trade that involved getting Rome's world map, and look at this:
I shall let that speak for itself.
So, I research up to the Industrial Age, all at 100% research, and occasionally selling techs at monopoly price to finance it. I research Steam Power, and the Gods of Coal have decided to amuse themselves.
I have two coals, and both are in potential Iron Works locations! But both sites would be pathetic. Sheesh. 
And to add further insult, they're on tiles I don't yet have roaded.
