Hardly a definitive authority on the topic but...
https://finalfantasy.fandom.com/wiki/TuralTural (...) known to the people of Eorzea as the New World (新大陸, Shintairiku?), is a continent in Final Fantasy XIV located far to the west of the Three Great Continents, across the ocean of the Indigo Deep.
GJJ's legendary feat is about uniting the peoples of Tural, but it's comparable to something like the EU more than the USA.
It's a little off topic but I'd say the whole thing with Heritage Found is more like the USA, where a monoculture develops which subsumes local cultures, tribes and traditions, effectively merging and eroding them over time through various social and material pressures (in DT, the time jump of 30 years serves as a device to convey that much).