Obviously the focus of the books is on the characters and school situated in England. But it seems to me that while there is mention of other schools, and quidditch teams, they are all European countries.
In the first book when Harry says he doesn't have any money Hagrid says this about banks
Hagrid: ...first stop fer us is Gringotts. Wizard's bank.
Harry: Wizards have banks?
Hagrid: Just the one. Gringotts. Run by goblins."
So in the entire wizarding world there is only one bank?
I can't think of a single reference to the American continents in all the books or movies, do the Americas even exist in the Harry Potter universe?
:)