This Thursday, many Americans will drink margaritas and eat tacos in celebration of Cinco de Mayo, which means May 5 in Spanish.
"But if you ask why is anyone celebrating, no one knows," says David Hayes-Bautista, an expert in Latin health and culture at the University of California, Los Angeles.
Often confused with Mexican Independence Day, which is September 16, Cinco de Mayo actually commemorates the victory of Mexican forces over the French in the Battle of Puebla on May 5, 1862. (Read more about the history and evolution of Cinco de Mayo.)
Though a minor victory, the Battle of Puebla became a lasting symbol of Mexican pride that evolved into a celebration of Mexican-American heritage. The holiday is not widely observed south of the border—except in the city of Puebla itself.
Raise a glass and celebrate Mexican history and culture with these photos from National Geographic's archive.