In one of the most important and controversial episodes in postwar Mexican history, on October 2, 1968, police and army units violently suppressed a demonstration in Tlatelolco Square in the heart of Mexico City. The government’s version of events differed starkly from those of eyewitnesses and the version that gained currency among much of the populace.
The crackdown contributed to a growing crisis of legitimacy for the ruling party, the Partido Revolucionario Institucional (PRI), fueling popular sentiments that the PRI was corrupt, dictatorial, and antidemocratic, and tarnishing Mexico’s image on the eve of the country’s hosting of the 1968 Summer Olympics.
The roots of the October 1968 events in Tlatelolco have been traced to the upsurge in student and worker democratic and anti-PRI activism from the late 1950s, including the Teachers’ Movement in 1958; the Railway Workers’ Movement in 1958–59; demonstrations in support of the Cuban Revolution (1959); a massive student strike at the National University (UNAM, spring 1966); and protest movements in the states of Puebla (1964), Morelia (1966), and Sonora and Tabasco (1967).
More immediate antecedents include the government’s mobilization of an antiriot paramilitary squad, the granaderos, in response to street fights between two Mexico City schools in July 1968, and again in response to student protests commemorating the anniversary of Fidel Castro’s 26th of July Movement. Tensions mounted throughout August as students held huge demonstrations at the UNAM and the National Polytechnic Institute.
The events prompted the formation of a National Student Strike Committee, which issued a list of demands that included disbandment of the granaderos and release of all political prisoners. An estimated 500,000 people, mostly students and workers, participated in antigovernment demonstrations in Mexico City’s central square (Zócalo) on August 27, to that date the country’s single largest mass protest.
Law enforcement agencies responded with tanks and armored cars, killing at least one student. In mid-September, President Gustavo Díaz Ordaz ordered 10,000 army troops to occupy the UNAM campus. Some 500 protesters were jailed, and in the ensuing weeks tensions throughout Mexico City ran high.
The exact sequence of events on the evening of October 2 in the Plaza de las Tres Culturas (Plaza of the Three Cultures) in the District of Tlatelolco, where 5,000 to 10,000 protesters had gathered, remains disputed. The next day the government claimed that terrorists had opened fire on the police from a nearby building and that police had responded to the unprovoked attack.
Most newspapers at the time reported from 20 to 28 protestors killed. Eyewitnesses recalled with near unanimity that police and army units had instigated the violence, dropping flares from helicopters before spraying machine-gun and small-arms fire indiscriminately into the crowd, killing hundreds.
The British newspaper The Guardian estimated after "careful investigation" that 325 were killed, a figure cited by Mexican writer Octavio Paz as the most plausible. In the ensuing days and weeks, thousands were jailed.
Memories of Tlatelolco remained fresh into the 1990s and after, evidenced by a 1997 congressional investigation into the massacre and the 2006 indictment of ex-president and then-interior minister Luis Echevarría for his role in the events, which remain a festering wound in the nation’s collective memory.