The Boston Red Sox will celebrate in one way or another the Mexican holiday called Cinco de Mayo that is now an adopted drinking and partying excuse in the United States. The Mexican holiday is in honor of a battle won against French forces in Mexico in 1862 and on (surprise) May fifth. My assumption is this holiday has its American roots in California with a large Mexican population and capitalism – that probably that has to do with promoting alcoholic beverages – most notably beer.
Mexico is a baseball hotbed and has long been a place where American players went in the winter to play or the Mexican League in the summer to make a living.