Second International Congress on Education of the Deaf
The Second International Congress on Education of the Deaf, commonly known as the Milan Conference or Milan Congress, was an international conference of deaf educators held in the Regio Istituto Tecnico di Santa Marta, Milan, Italy from 6 to 11 September 1880. After deliberations, the Conference declared that oral education (oralism) was superior to manual education (sign language) and passed a resolution banning the use of sign language in school.
Source: Wikipedia — Second International Congress on Education of the Deaf (CC BY-SA 4.0)