Boris Gudenuf
Deity
Looking at the previewed US, it seems at least one of the UU's is really strongly tied to the leader choice. The same could be said for Cleopatra's UA.
So I think some leader speculation is needed. For example:
England (Victoria) - Redcoats (since we got Frigate replacements in V)
- Except that the 'Red Coat' pre-dates Victoria by about a century and a half. They overlap, since the Brits didn't adopt the 'khaki' uniform color until more than half-way through Vicky's reign.
Note, though, that while the Rough Rider as an American UU is directly associated with TR, the P-51 is definitely NOT. Therefore, direct correspondence between Uniques and Leaders is not necessarily a guiding factor.
And, frankly, I hope the Uniques aren't 'set in stone' yet, because the 'Rough Rider' and P-51 are particularly Un-Unique American Unique Units:
Everybody built high-end piston-driven fighters in 1944 - 46. Except for range, there is nothing that makes the P-51 unique compared to Germany's Fw-190D, Britain's Spitfire XX-series, or the Soviet Union's La-7. Also, unless they dramatically change aerial warfare, who cares about fighter aircraft? It's the bombers that do the Dirty Work.
'Rough Riders' (to be precise, the First US Volunteer Cavalry Regiment) were semi-regular light cavalry that, in fact, fought their only battles on foot. ALL the US cavalry since the 1850s could fight on foot, and the Russian dragoons had been doing the same thing since Peter the Great. No Big Deal.
By comparison, there are just a few of the units that are Really Unique to America:
Rangers - Colonial and twentieth century: heavily armed Scouts that have the capabilities of very, very good infantry, paratroops (in the modern era) and scouts.
Pioneers Settlers that can defend themselves. - And how useful is That in Civ?!
Marines - only one other nation ever managed to put multiple Divisions of troops ashore against hostile forces: Britain. The US Marines can do amphibious assault, have their own air force, and the US military has been doing assault landings since Vera Cruz in the Mexican War!
B-17 - representing the fact that only Britain (again) ever developed a massive bomber force with the logistics, training, formation flying, pathfinder and specialized ordinance capabilities to deliver 'knock-out' blows to entire cities. Nobody else ever came close: the Luftwaffe made single raids that terrorized Rotterdam, Guernica, and Stalingrad, but their only long-term air assaults - against London and Moscow - were fiascos.
Supercarrier - the massive, modern floating air field, nuclear-powered and even capable of launching satellites. Again, nobody else has built anything quite like them.
I sincerely hope that the developers spend a little more time on the Uniques. It's hard enough 'boiling down' a civilization into 3 - 4 particular abilities or peculiarities: it's really bad if the 'peculiarities' you pick aren't particular to the civilization in question.