Haydée Gastelú was a co-founder of "Mothers of the Plaza de Mayo" ("Asociación Madres de Plaza de Mayo"), a movement of Argentine mothers who campaigned for their children who had "disappeared" during the military dictatorship, pursuing the government for answers from 1977 to 2006. Her son, Horacio Oscar García Gastelú, was one of the "desaparecidos" ("disappeared").