Cinco de Mayo, Spanish for "fifth of May", is a celebration held each year on May 5. It is celebrated nationwide in the United States and regionally in Mexico. The date is observed in the United States as a celebration of Mexican heritage and pride and to commemorate the cause of freedom and democracy during the first years of the American Civil War. Contrary to widespread popular belief, Cinco de Mayo is not Mexico's Independence Day, the most important national patriotic holiday in Mexico, which is celebrated on September 16.