Speaking as a non American, who has not had to learn very much about america at all...
This was pretty fun, and I did surprisingly well. I only made 9 mistakes on my first playthrough taking 4 mins and 20 secs.
Second playthrough I noticed the states came in a different order (nice touch). And I made only two mistakes, taking about the same time (4 secs longer).
The game is pretty solid, I wouldn't mind seeing something similar for european countries, or counties of britain. It's probably a pretty useful learning aid, and may be fun for kids, or good in classrooms.