Lots of us have heard of the Mexican holiday Cinco de Mayo, but not everyone knows what it celebrates. It is not, as some believe, Mexico's Independence Day. The festivities that occur on the fifth day of May commemorate a battle that was fought almost 50 years after Mexico declared its independence from Spain.

Throughout Mexico, as well as in many cities across the United States and any other country where there are people of Mexican descent, the fifth of May means partying in traditional Mexican style; but its significance goes beyond mariachi bands and pi√Īatas. In this edition of HowStuffWorks, you will learn about the roots of Cinco de Mayo and how this holiday is celebrated in North America.