Mujeres en Acción Solidaria (Women in Solidarity Action, MAS) was a Mexican feminist organization active in the early 1970s.
[3] Though the roots of MAS can be traced to the radical inclusivity of the Mexican student movement of 1968, the Tlatelolco massacre of October 1968 had led to a climate of fear at open protest.
Concerned friends of the organizers persuaded them to attempt to gain official permission to demonstrate.
On the day, the demonstration coincided with Miss Mexico contestants arriving at the monument to make an offering.
In 1977 it was integrated into the Coalición de Mujeres Feministas (Coalition of Feminist Women), refocussing its activity on reproductive rights.