Happy Cinco de Mayo!

From The Writer's Almanac:

Today is Cinco de Mayo, which commemorates the Mexican victory over the French in the Battle of Puebla in 1862, but is, in a more general way, a celebration of Mexican heritage and culture in the United States.

After a series of wars in the mid-19th-century, Mexico was reeling. President Benito Juarez announced that payment of foreign debts would be temporarily suspended in 1861, and the French navy showed up to demand repayment. As long as they were there anyway, Napoleon III thought it would be a good idea to replace the current government with one more favorable to French interests -- and France could also establish a base of operations to aid the Confederacy in the American Civil War.

In a David-and-Goliath battle, the 8,000-strong, well-armed French army was routed by 4,000 ill-equipped Mexican soldiers, and though it wasn't a decisive battle in the course of the war, it became a symbol of Mexican pride. It also kept Napoleon from aiding the cause of the Confederacy.

Cinco de Mayo isn't widely celebrated in Mexico outside the state of Puebla, but it has been adopted by many Americans regardless of their heritage, much like St. Patrick's Day and Oktoberfest. It's been celebrated in California since 1863, and grew in prominence in the rest of the country along with the Chicano movement of the 1940s. It wasn't until beer advertisers decided to promote the holiday heavily in the 1980s that American celebration of Cinco de Mayo became widespread.