Dia de Independencia

Here is a brief history of the significance of Mexico's independece, courtesy of <http://www.sanmiguelguide.com/tour-el-grito.htm>:

On September 16, 1810, Father Miguel Hidalgo y
Costilla, parish priest of the village of Dolores, gathered his congregation
of Indians and mestizos and called for Mexican independence, with the exile or arrest of all Spaniards (gachupines) in Mexico who had oppressed and exploited the native populations for hundreds of years. He ended his speech by calling out "Mexicanos, Viva Mexico!" (Mexicans, long live Mexico!) – which was doubly significant since the country was known as Nueva España (New Spain) at that time.
Though the criollos (Mexican-born people of Spanish heritage) had
already been plotting independence, this new movement was far more violent, and ultimately far more effective. From Dolores, the revolutionaries went to San Miguel de Allende, and from there to Mexico City, gathering more and more supporters. Along the way they acquired an banner with the image of the Virgin of Guadalupe, which became a rallying point. The Virgin of Guadalupe is the patron saint of Mexico, and a woman of color, an important symbol of Mexico in its own right.
After a long and bloody struggle, Mexico's independence was finally recognized in 1821 by the Spanish viceroy, 11 years after Father Miguel
Hidalgo's fateful decision. Ever since, Mexico has celebrated the
anniversary of "El Grito" in the Zocalo of Mexico City on the night of the 15th of September. The President of the Republic of Mexico starts the ceremony by ringing the actual bell from Padre Hidalgo's church and repeating the words of Miguel Hidalgo's call for independence, culminating at midnight with fireworks and cries of "Viva Mexico". Miguel Hidalgo's speech is repeated from the balconies of every Presidencia (Mayor's Office) in the country as part of the traditional independence celebration that are part of the Fiestas Patrias.