Cinco de Mayo, or May 5th, falls on Sunday this year. Although it is often mistaken as Mexico’s Independence Day, it actually commemorates the Mexican army’s victory over the French army at the Battle of Puebla on May 5, 1862.

The origins of what we call Cinco de Mayo can be traced back to the mid-19th century when Mexico was struggling with economic woes and political instability. At the time, Mexico had incurred significant debt to European countries, including France, Britain, and Spain.

In 1861, Mexican President Benito Juarez declared a moratorium on the repayment of foreign debts, which led to a military invasion by French forces. The French army, led by Napoleon III, aimed to establish a French-supported monarchy in Mexico, which would provide a valuable ally in the Americas.

However, the Mexican army, led by General Ignacio Zaragoza, fiercely resisted the French forces and defeated them at the Battle of Puebla on May 5, 1862. This victory, although not decisive in the war, became a symbol of Mexican resistance against foreign intervention and marked a significant historical moment for Mexico.

Cinco de Mayo remained a relatively minor holiday in Mexico until the late 20th century, at which point it gained widespread popularity in the United States. After the Mexican Civil War ended in 1915, many Mexican people came to the United States and settled in the southern states. When they came to America, they brought with them their customs, traditions, and holidays—including Cinco de Mayo.

The holiday became a way for Mexican-Americans to celebrate their culture and heritage, and to share it with their neighbors in the US. Additionally, the holiday’s popularity has been fueled by commercial interests, with many businesses using it as an opportunity to promote Mexican food, drinks, and other products.

Want to celebrate at home? Here’s a good margarita recipe from the Food Network: If you like margaritas with salt, rub the outside rims of your glass with a cut lime and dip each glass lightly into a plate of kosher salt. Then combine lime juice, Triple Sec, white (blanco) tequila, and ice in a blender for a frozen drink or a shaker for one on-the-rocks. Serve with some chips and salsa, and enjoy!