What is Las Madres de la Plaza de Mayo as noted in the book, Men Explain Things To Me?

Las Madres de la Plaza de Mayo was a group comprised of mothers who stood up against the military junta in Argentina during the dirty war that took place from 1976 to 1983. The military would make people “disappear” in a stealth manner so that no one initially knew they were missing, where they were taken or what fate befell them. These mothers protested in front of the presidential palace despite the threats they received and the assaults they suffered.