We hard barely left the forest of Chapultepec, we had walked only a few blocks when the lines began to grow. All along the Paseo de la Reforma, the sidewalks, the greens, the monuments, and even the trees were full of a multitude who within a hundred meters doubled our numbers. And from those dozens of people and then hundreds of thousands, you could hear only footsteps. . . . Steps, steps on the asphalt, steps, the sound of all the marching feet, the sound of thousands of feet that were advancing. The silence was more striking that the multitude. It seemed like we were trampling all the verbosity of the politicians, all the speeches that were always the same, all the demagoguery, the rhetoric, the piles of words never backed up by actions, the stream of lies, we were sweeping it all away under our feet.

This account comes from Enrique Krauze's great book, Mexico: Biography of Power.

Of course, 19 days later came the massacre in the Plaza de las Tres Culturas, which ended the student revolt.