Cinco de Mayo, or the Fifth of May, is a celebration held in commemoration of the Mexican Army's defeat of the French at the Battle of Puebla during the Franco-Mexican War. It wasn't a major strategic win, but it was definitely a symbolic one, with the Mexican force being made up of only about 2,000 men against a better trained French force of 6,000. The holiday came to the U.S. by way of California, which was still largely Mexican at the time, and the holiday evolved differently in both countries: in the U.S., it's become a celebration of Mexican culture and heritage (which a lot of people use as an excuse to get wasted), while in Mexico, it's mostly just celebrated in the state of Puebla with military parades, recreations of the battle, and other festivities.