Actually, Cinco de Mayo isn't a major holiday in Mexico. It isn't even an official holiday there. It is more of a regional thing, primarily in Puebla. The reason it seems like such a big deal in the U.S. over the past few years is two-fold: a good portion of the Mexican population currently in the U.S. is from Puebla, and the Mexican beer distributors in this country saw a way to create more business. I saw a report about it a year or two ago on Fox.
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