I would highly recommend the following essay by Oscar Casares from the Austin Chronicle: Holiday of Cinco de Mayo is minor event in Mexico. If anything, it underscores how Cinco de Mayo is probably a bigger deal in the United States than it is in Mexico (although granted, it is more in terms of eating tacos and drinking margaritas and beers than anything else):
Though many people in the U.S. regard this date as a celebration of Mexico’s independence, in truth, Cinco de Mayo marks the Battle of Puebla and the Mexican army’s defeat of a much larger and better-equipped French army attempting to conquer its weakened government. The victory was short-lived, as the French took over the country a year later and remained in power for the next three years. The battle itself reportedly lasted only from dawn to early evening on May 5, 1861. Compared to Mexico’s fight for independence against the Spanish empire, a struggle that lasted for more than 10 years, or the U.S.-Mexico War, which led to the defeated nation losing two-thirds of its territory — including those areas now known as Texas, New Mexico, Arizona, and California — the Battle of Puebla was little more than a skirmish in the country’s long and bloody history. Today in Mexico, Cinco de Mayo will be commemorated primarily in the state of Puebla and recognized during a small ceremony in the capitol.
In terms of up here in Gringolandia:
The date gained more attention in the 1980s when marketers, particularly beer companies, saw this as a perfect opportunity to capitalize on the celebratory nature of the holiday. This week Cinco de Mayo will be celebrated with festivals and parades in places like Raleigh, North Carolina; Midvale, Utah; Atlanta, Georgia; Omaha, Nebraska; some with large Mexican or Mexican-American populations but many without.
[…]
Of course, if you happen to not speak Spanish, Cinco de Mayo is much easier to pronounce, no matter of how many margaritas are involved. So a facility with the language and how this lends itself to marketing products around the holiday certainly must also play a role.
Just imagine a beer company trying to fit Dieciséis de Septiembre on a beer koozie.
Dieciséis de Septiembre is the more significant date in Mexico, i.e., the start of the struggle against the Spanish, which is a much bigger deal than Cinco de Mayo.
