What did Benito Juarez have to do with Cinco de Mayo?

Benito Juarez was President of Mexico, On July 17, 1861, he issued a moratorium stating that all foreign debt payments would be suspended for two years. In response, Britain, Spain and France sent naval forces to collect. Britain and Spain later withdrew, but France remained, resulting in the French-Mexican War.

It was during that war that the Battle of Puebla was fought and won against great odds by the Mexican forces. Cinco de Mayo is celebrated in recognition of that victory.