that's the Mexican Independence Day!
Okay, gotta give a quick history lesson.
In America, we erroneously believe that the 5th of May is MexIndependence Day. (Like that word I just made up? I certainly do. Better get a trademark on that bad boy.) It's not. MexIndependence Day is the night of the 15th and the day of the 16th of September, when a priest effectively issued the Latin American equivalent of the Declaration of Independence (called the Grito de Dolores
, or Cry of Pains (well, and Dolores, too, because that was also the name of the town the priest was from)). Father Manuel Hidalgo is basically their Thomas Jefferson. And it's the 15th and 16th.
The 5th of May isn't even really celebrated much in most of Mexico, only in the state of Puebla, where like forty years after their independence, the Mexicans fought a battle to expel Maximilian's (the puppet dictator from France) army. Most Mexicans don't celebrate Cinco de Mayo, only in Puebla do they actually do so. It would be like the equivalent if we celebrated the day old Stonewall Jackson kicked British ass in New Orleans during the war of 1812, and the rest of the world thought of that
as our Independence Day.
Any way, common misconception that gets foisted on us by all the department stores and restaurants having Cinco de Mayo sales and specials. Meanwhile, all the Mexicans who AREN'T from Puebla are too busy trying to figure out why us Americans give a damn about it.