Following the 1892 Sasquatch uprising, MACUSA moved its headquarters from Washington to the newly built Woolworth Building in New York City (Pm).
When the building was under construction, wizards joined the construction crew. Thanks to these undercover wizards, the Woolworth building was not only a building for No-Majs, it also specially accommodated MACUSA when activated by spells (Pm).
The precise date is uncertain. MACUSA agents infiltrated the construction crew when the Woolworth Building was being built, and this appears to leave a considerable gap between the Sasquatch rebellion and the move to New York since, if going by a real world timeline, construction started on the building in 1910, it was completed in 1912, and it opened in 1913 (source: Wikipedia).