I have always wondered why in the USA some people believe the 5th of May it's Mexico's celebration of Independence (which is actually on September 16th). What we celebrate is a victory in 1862 over the French army, when they invaded our territory (the effects of this battle didn't last long, but in the end the French did go away).
It used to be an official holiday, but a few years ago, they made it disappear from our calendar.
I just found this article with history on this date as a celebration for Mexican culture, so I thought it was worth sharing:
http://news.yahoo.com/cinco-mayo-ple...171319825.html