Cinco de Mayo is actually a regional holiday, which is primary celebrated in the state of puebla. Although it is not an obligatory celbrated mexican holdiay it serves to commemorate an initial victory of Mexican forces led by General Ignacio Zaragoza Seguin over French forces in the Battle of Puebla on May 5, 1862. I am pretty sure after the battle was won they all went out for a drink.
Comments
it's just an excuse to have margaritas and mexican food. ;-))
http://en.wikipedia.org/wiki/Cinco_de_Mayo
Most Americans are under the impression that it is the Mexican Independence day, but that's not the case as I'm sure you know.