¡Viva México! is what you'll be hearing all day today if you are celebrating the Independence Day of our neighbors down south.
The traditional celebration has all of the Mexican citizens gathering at the Zócalo plaza in México City. The President then does what is called "El Grito" based on "El Grito De Dolores" which is what started the Mexican War Of Independence in 1810.
Miguel Hidalgo y Costilla and several criollos were involved in a planned revolt against the Spanish colonial government, when several plotters were killed. Fearing his arrest, Hidalgo commanded his brother Mauricio, as well as Ignacio Allende and Mariano Abasolo to go with a number of other armed men to make the sheriff release the pro-independence inmates there on the early morning of September 16. They managed to set 80 free. Around 6:00 am, on September 16, 1810, Hidalgo ordered the church bells to be rung and gathered his congregation. Flanked by Allende and Juan Aldama, he addressed the people in front of his church, urging them to revolt.