On this day in 1862, in a town called Puebla, a ragtag Mexican army defeated an invading French army that was better equipped and twice as big.
France eventually won the war and went on to rule the country for a few years, but the unlikely defeat at the so-called Battle of Puebla made it into the history books as Cinco de Mayo.
It was an underdog victory — no more, no less.
U.S. Latinos in the late 1960s would later cite it, if not cling to it, in their fight for equal rights as the movement really put Cinco de Mayo on America's radar, mostly in the Southwest.
Over the years, it would gradually become commercialized (not unlike the Super Bowl), with its countless advertisements of beer mixed in with stereotypical sombreros and mustaches resembling Pancho Villa's. (For the record, even Pancho Villa wouldn't be born until 1878).
Often, Cinco de Mayo is confused with Mexico's Independence Day, which is Sept. 16, 1810.
That's the day Mexico began its pursuit for independence from Spain — much like the United States declared its own independence on July 4, 1776.
But the real confusion these days surrounding Cinco de Mayo is whether it's an actual Mexican holiday — or an excuse for everybody to just hoist a few Mexican imports like Corona and Dos XX and tune out the rest of the world.
It's true that Cinco de Mayo is barely recognized or celebrated in Mexico, except perhaps in Puebla, the old battle site an hour west of Mexico City.
But in California and other states in the Southwest, the holiday has been going strong, mostly among Mexicans who want to celebrate their heritage or among Americans who want to jump on the party bandwagon.
Hence, it's referred to by many in the drinking circles as Drinko de Mayo — not too far off from the kind of excitement associated with St. Patrick's Day.
"We're going to have $3.95 margaritas instead of the usual $6," said Gabe Lozano, manager of El Ranchito, a Mexican restaurant in Newport Beach.
And Dos XX beers are going for $4, he said.
Asked if he knew anything about the history of the holiday, Lozano said he didn't but then added:
"It's a reason to celebrate," he said. "We cater to our crowd."
And that crowd is mostly white middle class, often of the surfer persuasion — although Jose Vazquez will be in the back, cooking the meals.
Vazquez lives on Costa Mesa's Westside, and earlier Tuesday he said he wasn't going to be celebrating Cinco de Mayo because he was going to be working at the restaurant.
And yet even Vazquez, admittedly, couldn't tell you much about the history of the holiday, although he did know that Lazaro Cardenas, the Mexican president in the 1930s, hailed from his home Mexican state of Michoacan.
Nor could Gabriela Lopez, 23, an Estancia High School graduate, tell you the particulars of Cinco de Mayo.
"I used to go clubbing with my friends," she said as she sat behind the counter of El Farito, a meat market on Costa Mesa's Westside. "But now I don't do anything. I'm not sure what it means, to be honest, and my parents came from Mexico."
And that's OK.
Very many Americans would be hard pressed to tell you about the particulars of, say, the American Revolution or the battle at Valley Forge. You either like history or you don't.
But if you like beer, you can bet that quite a few Mexican restaurants around town will have something in store for you to celebrate today, Lozano said.