Cinco de Mayo’s rise in popularity has its roots in the U.S. Civil War. In 1862, the Battle of Puebla saw a massive French army fall to very determined fighters in Puebla. Outnumbered 2 to 1, a tiny Mexican force held its own and did the seemingly impossible.

The story of this success became an inspiration for Mexican soldiers fighting for the Union in the Civil War. The spirit of May 5th, and the resistance against the French, became a rallying cry for Union soldiers. Today, Cinco de Mayo is celebrated in the United States as a day to honor Mexican heritage. While it’s still an important day in Puebla, May 5th is celebrated more widely in the U.S. than in the country that inspired it.