Cinco de Mayo is incredibly popular in the US, though many Americans have some pretty serious misconceptions about its origins and meaning. No, it doesn't commemorate when Mexico gained its independence from Spain. (That's marked on Sept. 16.)
It's not even a major event in Mexico.
The May 5 holiday honors the Battle of Puebla, when vastly outnumbered Mexican forces repelled French Emperor Napoleon III's troops in 1862 during the Second Franco-Mexican War.
How did a clash south of the border come to be such a huge day of partying in the US? Read on to find out.
What does Cinco de Mayo represent?
Mexico declared its independence in 1821. By 1861, though, the financially struggling country had defaulted on debt payments to several European nations. France's Napoleon III, nephew of Napoleon Bonaparte, decided to use the outstanding debt as a pretense to invade and extend his overseas empire.
Napoleon's troops stormed Veracruz and drove Benito Juárez, Mexico's first indigenous president, into exile. Emboldened by their early victory, French forces under General Charles de Lorencez attacked Puebla de Los Angeles, about 80 miles outside Mexico City, on May 5, 1862.
Juarez sent a ragtag army of Mexicans and Zapotec Indians to defend the town under the banner of General Ignacio Zaragoza. The battle lasted from dawn to sunset and, though they were outmanned nearly 2-to-1, Zaragoza's troops repelled Lorencez's troops.
The battle wasn't a decisive victory -- in fact, the French recaptured Puebla a year later -- but many Mexicans saw it as a symbol of throwing off the shackles of colonialism and oppression. Four days later, on May 9, 1862, Juárez declared Cinco de Mayo a national holiday.
French troops fully withdrew from Mexico in 1867, and Maximilian I, the Austrian archduke Napoleon installed as the country's emperor, was eventually captured and executed.
In honor of the Mexican victory, Puebla de Los Angeles was renamed Puebla de Zaragoza, and Cinco de Mayo was made a national holiday.
Why is Cinco de Mayo celebrated in the US?
As the French and Mexicans were battling, the US was embroiled in the American Civil War. Napoleon III had aligned with the Confederacy and planned to supply Southern states with weapons in return for cotton, which was being blockaded by the Union.
The loss at Puebla and the resources Napoleon expended in Mexico helped derail his strategy to continue northward and bolster the Confederacy.
US citizens of Mexican descent overwhelmingly supported the Union, according to David E. Hayes-Bautista, director of the Center for the Study of Latino Health and Culture at the UCLA School of Medicine. They voted for Abraham Lincoln, and many served in the Union army, navy and cavalry.
News of the decisive victory in Puebla "electrified Latinos in California, Nevada and Oregon into redoubling their efforts to defend freedom, equality and democracy in both the United States and Mexico," Hayes-Bautista told CNET.
For his book El Cinco de Mayo: An American Tradition, he traced period newspapers showing that Cinco de Mayo celebrations were held in Los Angeles and other parts of the West almost as soon as the battle in Puebla was over.
"Every Cinco de Mayo, Latinos marched through the streets of cities, towns and mining camps to let the world know where they stood on the issues of the American Civil War and the French Intervention in Mexico," Hayes-Bautista said.
By 1910, the Mexican-American veterans of the American Civil War were dying off, and a new wave of immigration was coming to California amid the Mexican Revolution.
"These new arrivals noticed the Cinco de Mayo celebrations here in California, and began to join them," Hayes-Bautista said. But they repurposed the celebrations with songs, music and images of the Mexican Revolution, he said.
In the 1960s, leaders in the Chicano movement repurposed Cinco de Mayo again, as a symbol of cultural pride and resilience as they advocated for farm workers' rights, educational and economic opportunities and other social and political causes.
"The David versus Goliath story fittingly mirrored the struggle for civil rights," Kirby Farah, an anthropologist at the University of Southern California, wrote for The Conversation.
The commercialization of Cinco de Mayo
For generations, Cinco de Mayo wasn't widely known in the US outside of Mexican American and Central American immigrant communities. Then, in the 1980s, as Latinos became a larger economic force in the country, beer companies saw an opportunity. In 1989, the Gambrinus Group, the Texas importers of Corona and Negra Modelo, launched an ad campaign encouraging Mexican Americans to drink Mexican beer on the holiday.
The marketing was soon broadened to reach Americans of all backgrounds, and, in 1993, Gambrinus marketing director Ron Christesson told Modern Brewery Age magazine that Cinco de Mayo was "becoming one of the beer industry's biggest promotions."
It was in this era, Hayes-Bautista said, that Cinco de Mayo "became highly commercialized into 'Drinko de Mayo.'"
Americans spent more than $600 million on beer on Cinco de Mayo in 2013, according to market research company Nielsen. That's more than they did during the Super Bowl, the Fourth of July or St. Patrick's Day that year.
"Corona is the first thing that comes to mind when customers think Cinco de Mayo," Gambrinus marketing director Don Mann said in 2006.
This year, Corona is sponsoring a "Corona de Cinco" campaign on its website that included Old El Paso recipes and a chance to win $25 Uber gift cards.
The liquor delivery app Drizly is pushing tequila on its home page, encouraging customers to "make your Cinco succulent" with top-shelf tequilas and mezcals. (Americans also consume roughly 8.7 million gallons of tequila on May 5, Loop Insights reported.)
How to celebrate Cinco de Mayo the right away
Hayes-Bautista would like to shift Cinco de Mayo away from liquor companies and restaurant chains and back in the hands of the community.
"A fiesta is fine, but we should remember why we are celebrating," he said. "While the Fourth of July has been highly commercialized, beneath it all we do remember that the day has something to do with the founding of the United States of America and the Declaration of Independence."
Cinco de Mayo "took off in the US as a way for a minority to show its pride -- like St. Patrick's Day," he told CNET. "And like St. Patrick's Day, it started to be promoted by marketing companies. I guess they did their job well."
Rivas-Solis said he believes there's nothing wrong with embracing the revelry of the day, so long as it "comes from the heart and isn't just making fun."
"Mexicans love to have parties," he said. "There is a way to make the day more cultural and political, but we always love to celebrate."
He suggests Americans who want to honor the Battle of Cinco de Mayo learn about its origins and other aspects of Mexican culture.
"If you're going to drink tequila, learn about the centuries of culture behind it, learn about Jalisco. If you're going to wear a sombrero, learn where it comes from."
Rivas-Solis also makes a bid for visiting Mexico and exploring its history and culture firsthand.
"San Miguel de Allende is the cradle of Mexican independence and has an incredible Day of the Dead celebration," Rivas-Solis said. "In Mexico City, you have Chapultepec Castle, which Emperor Maximilian had constructed."
Puebla itself is beautiful, he added, with many sites from the colonial era still preserved. And of course, Puebla still honors Cinco de Mayo -- with historical reenactments, mariachi music and a festival devoted to mole poblano, a savory chile and chocolate sauce that's become synonymous with the region.
"It's where mole is from," Rivas-Solis said. "The gastronomy is amazing. And there are these incredible fields of flowers -- the flowers you see used in the Day of the Dead come from Puebla."