In 1777, MACUSA President Elizabeth McGilliguddy sent a message to the Ministry of Magic in London asking if they planned to intervene Revolutionary War between the Thirteen Colonies and England. A reply was sent back that said “Sitting this one out,” to which she famously replied, “Mind you do” (Pm).
McGilliguddy also presided over the “Country or Kind” debate that same year, during which North American wizardry decided not to officially interfere in the Revolution. However, many witches and wizards secretly helped protected their No-Maj neighbors (Pm).
Although not stated in the History of MACUSA, we can infer from the list of Ministers for Magic on Pottermore that McGilliguddy's counterpart with the Ministry of Magic and possible correspondent during the American Revolution was Maximilian Crowdy, who served from 1770 - 1781 (Pm).