When did Mexico declare victory over France?

May 5, 1862. This victory is special because, before that, the French had never lost, but this time, they were outnumbered by the Mexican army. The President, at the time, President Juarez, saw the importance of the victory that he declared the day a national holiday on September 16, 1862.

This holiday is what we know today as Cinco de Mayo. Not only is it celebrated in Mexico, but many all over the world celebrate the holiday, from having parades and ceremonies to decorating and dressing up in honor of Mexican culture.