Each May 5th Cinco de Mayo celebrations are held in cities throughout the United States. But few people know the holiday's significance. It's a story that began on a sweltering morning May 5 1862 in the city of Puebla Mexico and surrounding forts when an ill-equipped Mexican Army along with Zacapoaxtla Indians and regular citizens beat the invading French Army. Filmed in Mexico and the U.S. this is the riveting story-from events leading up to the bloody battle and the aftermath. Today the memory of French occupation has faded except for Cinco de Mayo-the day the Mexicans defeated the most powerful army in the world.