Get out your red, white and green for Cinco de Mayo. Your pets can celebrate with you. Cinco de Mayo—or the fifth of May—commemorates the Mexican army's 1862 victory over France at the Battle of Puebla during the Franco-Mexican War (1861-1867). A relatively minor holiday in Mexico, in the United States Cinco de Mayo has evolved into a celebration of Mexican culture and heritage, particularly in areas with large Mexican-American populations. Cinco de Mayo traditions include parades, mariachi music performances and street festivals in cities and towns across Mexico and the United States.