Final answer:
The wizarding historian known for writing about the Scourers in the US is J.K. Rowling, the author of the Harry Potter series.
Step-by-step explanation:
The wizarding historian known to have written extensively on Scourers in the US is named J.K. Rowling. Rowling is largely known for her Harry Potter series, where she delves into the history of magic and the wizarding world.
The Scourers were a group of rogue and unscrupulous wizards who played a significantly negative role in the wizarding history of North America, practicing dark magic and contributing to witch hunts.He documented their role in American magical history and their impact on the lives of wizards and witches in the United States.