I cannot find what controls the population of the drop-down menu for COUNTRY when a customer is creating a new account. The way it is, the drop down menu has all countries listed. I deleted a few names from the Locations/Countries list and this works. I can just delete all countries from this list except the US if I need to. It probably wouldn't take more than a half hour. If I want to sell into Canada and Mexico later I could just add those back to the list.

Is this the only way, or is there a simpler, cleaner method?