If The History of Magic in North America has taught us anything, it's that America's magical history is dark and full of terrors. Think of the Scourers like the OG Death Eaters. Their sole purpose in life was to exterminate wizards and teach their descendants to do the same. They've been the cause of interminable pain among North American wizarding communities since the Salem Witch Trials in 1692, so it makes sense that the Magical Congress of the United States of America (MACUSA) would eventually do something radical to protect their own.
In the third installment of J.K. Rowling's North American–wizardry history lesson, now live on Pottermore, the Harry Potter author delves into Rappaport's Law, a law passed in 1790 that institutionalized segregation of the wizarding and No-Maj communities.
The law was passed following one of the most catastrophic breaches of the International Statute of Secrecy the wizarding world had ever seen. To make matters even worse, the breach came from within MACUSA itself, when a young witch named Dorcus Twelvetrees -- the daughter of President Rappaport’s trusted Keeper of Treasure and Dragots (the Dragot is the American wizarding currency), Aristotle Twelvetrees -- fell in love with a Scourer descendant.
Now, Dorcus didn't know this at the time of their courtship -- she was far too dim-witted to figure that out -- but the handsome No-Maj she fell in love with, called Bartholomew Barebone, was convinced that all witches and wizards were evil. Bartholomew used Dorcus for vital information about the wizarding world, including "the secret addresses of both MACUSA and Ilvermorny, along with information about the International Confederation of Wizards and all the ways in which these bodies sought to protect and conceal the wizarding community."
When he had gathered all the information he could from Dorcus, Bartholomew stole her wand and showed it to the press. A few of the newspapers published the photos. To further get the No-Maj population on his side, Bartholomew printed leaflets with the names and places where wizards and witches in the community usually congregated. He distributed these leaflets widely in the hopes to galvanize the No-Majes into action.
With its address made public to No-Majes, MACUSA was forced to move premises. As for Bartholomew Barebone, the man was later imprisoned for shooting at a group of No-Majes he mistakingly thought were MACUSA wizards. But the damage to the wizarding community had already been done.
"As President Rappaport was forced to tell the International Confederation of Wizards at a public inquiry, she could not be sure that every last person privy to Dorcus's information had been Obliviated," Rowling wrote. "The leak had been so serious that the after-effects would be felt for many years."
Enter Rappaport's Law. The law enforced strict segregation between the No-Maj and wizarding communities, meaning that Wizards were no longer allowed to befriend or marry No-Majs. "Communication with No-Majs was limited to that necessary to perform daily activities," Rowling wrote.
Whereas European wizards and witches could fraternize with their Muggle brethren, American wizards were restricted from such activity, further pushing the American wizarding community underground. The same could be said for MACUSA, which acted completely independently of the No-Maj government. Such actions were unheard of in the Old World, where "there had always been a degree of covert cooperation and communication between No-Maj governments and their magical counterparts."
American wizards, however, kept to themselves -- and as time went on, a growing resentment towards No-Majes started to emerge.