So the new J.K. Rowling 'story' about Native American wizards is ... not great
Three hundred years in 413 words, which casually reveal that wizards in Europe and Africa (sorry, wizards on other continents! Apparently you weren't invited) knew about Native American wizards long before European explorers ever "discovered" them, thanks to "various modes of magical travel."
Things quickly go wrong after that opening. Basically, every Native American tribe is lumped into the category "Native American," which may make it easier to describe a very large and diverse group of people when you're trying to churn out some movie marketing material (which is, essentially, why this History of Magic in North America exists in the first place -- be sure to watch Fantastic Beasts and Where to Find Them coming to a theater near you on November 18!!!), but does a real disservice to the thousands of Native American tribes across North America that each had their own traditions and culture and have now been lumped together as if those distinct identities never existed.
Even my fifth grade history class went into more detail about Native Americans than this. Coming from a woman who devoted hundreds of pages to the ins and outs of a sport that doesn't even exist, it's somewhat disappointing.
We also learn that the Navajo "skin walker" legend comes from Animagis (wizards who can transform into animals) and that Native American wizards were better at potions and "plant magic" than European wizards, but couldn't figure out how to use a wand until the Europeans showed it to them. The end!
There are three more "stories" set to be released on the Pottermore website over the next three days that will presumably shed a bit more light on American history, if their titles and descriptions are anything to go by. They appear to focus solely on the United States, however, even though the series is supposed to focus on the history of North America, which includes other countries, such as Canada or Mexico.
If you had doubts that the author of such a quintessentially British book series could do the same for America in her screenwriting debut, then The History of Magic in North America should make you very worried indeed.