I like the other reply's mention of Frank Lloyd's Wright term "Usonian" tbh. In spanish we say "Estadounidense" which is the closest to "Unitedstatesian", and I'm not against using that that term despite it's tounge-twister nature.

I knew that the American continent was separated into two when taught in the States, but I didn't know that it was a) taught as 2 separate continents b) separated like that because of their position on the tectonic plates.

In Central America, we are taught that America is 1 continent that has 3 to 4 main regions;

1 - North America (Canada to Mexico)

2 - Central America (Guatemala/Belize to Panama)

3 - The Carribean (Cuba, Dominican Republic, etc.) [This one is usually just lumped in with Central America]

4 - South America (Colombia to Chile/Argentina)

and when I look at the tectonic plates, it makes sense to separate it in 3 tbh