Historians place the blame for the rebellion on Irene Kneedander, Head of the Body for Protection of Magical Species (Humanoid), whose interpretation of her job title had involved attacking any Sasquatch that ‘stepped out of line.’ The arrival in Washington of the Sasquatch necessitated mass Obliviations and extensive repairs to headquarters.
-- Pottermore: MACUSA
An uprising by the hairy giants of North America which caused the Magical Congress of the United States (MACUSA) to move operations from Washington to New York City (Pm).
The blame for this is generally placed on Irene Kneedander, Head of the Body for Protection of Magical Species (Humanoid) at the time, who attacked Sasquatches who “stepped out of line” (Pm:MACUSA).
Sasquatch: from the Salish Tribes of the Pacific Northwest sæsq'ec meaning "big hairy man"
The origin of the name might lead to the conclusion that the "Washington" mentioned as the previous location of MACUSA before the Sasquatch Rebellion was in the Pacific Northwest. But some readers have concluded that the author meant Washington D.C., the location of the NoMaj government and closer to the location of Ilvermorny Wizarding School. While there have been tales of tall hairy creatures in the Eastern United States with sightings that persist up till today, the use of the word "Sasquatch" more likely connects the rebellion to Washington State.