Although she's long finished writing the series, J.K. Rowling seems to delight in dropping ad hoc Harry Potter clues on Twitter. Most recently, the author tweeted about a key plot point in Fantastic Beasts and Where to Find Them: Main character Newt Scamander will meet American wizards who were educated at an American school of wizardry. In other words, there's an American Hogwarts.
Rowling was casually responding to fans' questions when she let slip the existence of a U.S. school.
.@MrBanankartong That information will be revealed in due course.— J.K. Rowling (@jk_rowling) June 6, 2015
.@tannerfbowen No, but he's going to meet people who were educated at [name] in [not New York].— J.K. Rowling (@jk_rowling) June 6, 2015
In other words, [name] in [not New York] definitely exists! Rowling then revealed that the school's name is "of immigrant origin" and the type of magic practiced there has to do with Native-American culture.
.@loonyloolaluna If I answer that fully it will reveal the location of the school, but you can take that as a yes!— J.K. Rowling (@jk_rowling) June 7, 2015
.@loonyloolaluna Oh wait - did you mean the NAME is of American Indian origin? It isn't. The name is of immigrant origin.— J.K. Rowling (@jk_rowling) June 7, 2015
.@loonyloolaluna However, indigenous magic was important in the founding of the school. If I say which tribes, location is revealed.— J.K. Rowling (@jk_rowling) June 7, 2015
She's understandably evasive, so eager Potter fans will have to wait until Fantastic Beasts is released for full details. Rowling is writing the screenplay (her first), so, who knows, she might be making everything up as she goes along, American Hogwarts included.