Cinco de Mayo commemorates the Battle of Puebla, which took place in 1862. But Mexico had been independent from Spain since 1810, so what made this date so important? While the American Civil War was unfolding in the north, Mexico was facing troubles of its own as President Benito Juarez canceled his country's payments to France, Spain, and England—and France wasn't going to let that slide. Emperor Napoleon III (the nephew of the guy with the funny hat) sent the largest army in the world at the time to Mexico's shores, intent on living up to the original Napoleon's dreams of world domination. But the French miscalculated the loyalty of the people of Puebla, and found themselves outmatched by an underdog force of citizen-soldiers. The day of the French retreat rallied the nation and bolstered a sense of national pride. Though the French would launch a more successful invasion in later years, they'd never hold on to their American territories for long. It's easier to just let Mexico be Mexico.
You'd be hard pressed to find a celebration of Cinco de Mayo in modern Mexico—at least, outside of Puebla, where it's a source of regional pride. So why is it so popular in the United States and elsewhere? That question has two answers. In the 1940s, Cinco de Mayo began to be recognized among Chicano activists as a uniquely Mexican celebration. In the '50s and '60s, the holiday's popularity grew thanks to the U.S.'s Good Neighbor policy, which promoted cultural and commercial exchange between the two countries. But it was a series of marketing events promoted by Miller and Anheuser-Busch in the early 1980s that transformed Cinco de Mayo from a triumph over an invading empire into a triumph over the concept of good taste. What we're saying is, maybe you should leave your novelty salsa-filled sombrero at home this year.