I met a group of people last year when I went over to see family that thought Spain was in South America.
Alot of parts of America (such as the one I grew up in) have an extrememly shitty geographical education system, it basically doesn't exist, so alot of Americans grow up not knowing alot of basic stuff about the world. I think maybe alot of them dont see any need to know anything outside their own glorious country.
I am of course am only sharing my opinion about a minority, and in no way believe the USA is full of people who know fuck all about the rest of the world.