The celebration of Cinco de Mayo primarily occurs in the state of Puebla, where the unlikely victory against the French army occurred at the Battle of Puebla.
Cinco de Mayo has been Americanized.
In the United States, Cinco de Mayo is sometimes mistaken for Mexico's Independence Day which actually occurs on September 16th.
It has been turned into a celebration of the Mexican-American culture in the U.S.
Americans celebrate by going to local Mexican restaurants, eating Mexican food, drinking tequila and margaritas, and listening to mariachi bands.
Cinco de Mayo parties or "fiestas" are also held to celebrate the 5th of May.
When I was living in Mexico I was supposed to be in Mexico City on Cinco de Mayo, but I ended up flying back to Oklahoma to visit my family and see my mom for Mother's Day.
Some friends were having a Cinco de Mayo fiesta that night and I wanted to go see everyone that I hadn't seen in months.
We had a mustachin' good time....
Turn that mustache upside down :)