Bloody Brits...

[Gawdzilla Sama]

...seriously, a simple Google would have worked.

Origins

The Magical Congress of the United States of America, known to American witches and wizards by the abbreviation MACUSA (commonly pronounced as: Mah – cooz – ah) was created in 1693, following the introduction of the International Statute of Wizarding Secrecy. Wizards worldwide had reached a tipping point, suspecting that they could lead freer and happier lives if they built an underground community that offered its own support and had its own structures. This feeling was particularly strong in America, due to the recent Salem Witch Trials

[The Valkyrie]

...seriously, a simple Google would have worked.

Origins

The Magical Congress of the United States of America, known to American witches and wizards by the abbreviation MACUSA (commonly pronounced as: Mah – cooz – ah) was created in 1693, following the introduction of the International Statute of Wizarding Secrecy. Wizards worldwide had reached a tipping point, suspecting that they could lead freer and happier lives if they built an underground community that offered its own support and had its own structures. This feeling was particularly strong in America, due to the recent Salem Witch Trials

I'm going to go with the Christians here and blame the Jews.

[Alex K]

I feel like I am missing some context here.

What what in the what what?

[The Valkyrie]

I feel like I am missing some context here.

What what in the what what?

Well, when a mummy and daddy love each other very much...

[Alex K]

I feel like I am missing some context here.

What what in the what what?

Well, when a mummy and daddy love each other very much...

Now I don't know what the thread is about and have nightmares.

[The Valkyrie]

Well, when a mummy and daddy love each other very much...

Now I don't know what the thread is about and have nightmares.

I aim to please.

[Gawdzilla Sama]

If you visit Pottermore.com all will be revealed. Including J.K.'s appalling lack of historical knowledge.

[vorlon13]

I said, what what, in the butt
I said, what what, in the butt
I said, what what, in the butt
I said, what what, in the butt
You wanna do it in my butt, in my butt?
You wanna do it in my butt, in my butt?
You wanna do it in my butt, in my butt?
Let's do it in the butt, okay
I feel you watching me
Over there
Come to me
If you care
Don't sit and stare
It's just not fair
Make your move
If you dare
What what
I said, what what, in the butt
I said, what what, in the butt
I said, what what, in the butt
I said, what what, in the butt
You wanna do it in my butt, in my butt?
You wanna do it in my butt, in my butt?
You wanna do it in my butt, in my butt?
Let's do it in the butt, okay
It's okay
To have a little fight
Don't you worry
I won't bite (Not that hard)
If you want it
I'll give you power
Just be gentle
I'm delicate like a flower
I said, what what, in the butt
I said, what what, in the butt
I said, what what, in the butt
I said, what what, in the butt
You wanna do it in my butt, in my butt?
You wanna do it in my butt, in my butt?
You wanna do it in my butt, in my butt?
Let's do it in the butt, okay
I will give you what you need
All I want is your big fat seed
Give it to me, if you please
Give it to me, if you please
I will give you what you need
All I want is your big fat seed
Give it to me, if you please
Give it to me, if you please
What what, in the butt
I said, what what, in the butt
I said, what what, in the butt
I said, what what, in the butt
You wanna do it in my butt, in my butt?
You wanna do it in my butt, in my butt?
You wanna do it in my butt, in my butt?
Let's do it in the butt, okay

[Gawdzilla Sama]

You forgot the "ifs" and the "ands".

[Rev. Rye]

So, apparently, Gawjira here was shocked that it apparently took 1693 for the wizarding community to go underground, when it's probably on the tail end of the big witch-hunt craze? I can understand that the American version would form in 1693, but somehow, I'm fairly certain the tipping point worldwide would have to be a hell of a lot longer ago.

Also, this appears to be supplemental material for Fantastic Beasts and Where to Find Them.