Saturday is Cinco de Mayo, a day often mistaken in the United States for Mexico’s Independence Day. In fact, the holiday had its origin more than 50 years after the date associated with the country’s independence. So here’s what you need to know about Cinco de Mayo, including its evolution into a major economic driver for business owners and beverage companies across the United States.

What is the significance of Cinco de Mayo?

Cinco de Mayo, which isn’t widely celebrated in Mexico, commemorates an underdog victory over France in the Battle of Puebla on May 5, 1862. The victory was galvanizing for the Mexican forces — and for those supporting them from afar — but it was short-lived, as France later occupied Mexico for a few years. Still, Cinco de Mayo continued to be celebrated in Puebla and, perhaps more significantly, by Mexican-Americans north of the border.

So when is Mexico’s Independence Day celebrated?

The country’s Independence Day is Sept. 16, now a national holiday. On that day in 1810, a priest named Miguel Hidalgo implored Mexico to revolt against Spain, leading to the War for Independence, which ended in 1821.

When did Cinco de Mayo gain popularity in the United States?

In the early 1960s, many Mexican-American activists entrenched in the country’s growing civil rights movement used the day as a source of pride. Close to two decades later, in 1989, an ad campaign by an importer of beers like Modelo and Corona was introduced around the day. The campaign was initially targeted toward Latinos but eventually broadened with print and TV ads. This year, Corona’s website featured a ticking “Countdown to Corona de Mayo” in the hours leading up to May 5.

The commercialization of Cinco de Mayo (and criticism of cultural stereotypes) has taken off. The research firm Nielsen reported that in 2013 Americans bought more than $600 million worth of beer for Cinco de Mayo, more than for the Super Bowl or St. Patrick’s Day.

David Hayes-Bautista, a professor at U.C.L.A., published a book in 2012 titled “El Cinco de Mayo: An American Tradition.” In the book, he called “Cinco de Mayo” a “fake holiday recently invented by beverage companies.”

The holiday’s evolution from an earnest show of patriotism to a chiefly corporate celebration has been fitful, to say the least.

“I’m trying to get a better sense of how that became so thoroughly lost,” Dr. Hayes-Bautista said in a phone call from Puebla, the site of the 1862 battle. “It’d be like if the Fourth of July were reduced to beer and hot dogs.”

Do Latinos still celebrate Cinco de Mayo?

Dr. Hayes-Bautista said many Latinos specifically avoid observing the holiday, partly because of a generational forgetfulness about the holiday’s Civil War origins.