Cinco de Mayo is not a nation wide holiday in Mexico no matter what Kenny Chesney or the Most Interesting Man in the word would like you to believe. It is a date that is special to the Mexican State Puebla. In May of 1862 the French army, who was at that time still a kick ass military forces was marching towards Mexico City to collect unpaid debt that Mexico owed to France. Mexico was essentially broke. Along the way to Mexico City, the French Army passed the state of Puebla where a group of approximately 3000 farmers, armed with old rifles and machetes defeated the "superior" French Army of over 8000 troops and drove them back toward the coast. Unfortunately the French returned about a year later with 30,000 troops and captured Mexico City. The French maintained rule for 3 years. The Mexican people then were able to overthrow the French with aid from the USA now that our Civil War was over in 1866.
The Battle Puebla is remembered each May 5th, mainly in the State of Puebla. But it commemorates an event that served to bolster the Mexican resistant movement and became Mexico's David vs Goliath story. Ironically it is their "Remember the Alamo" It also served as the launch point for a young officer who was an excellent leader during the battle named Porfiro Diaz. Diaz became president of Mexico in 1876 and ruled for 35 years, till 1911.
So now that you know the real reason behind CINCO DE MAYO.... Enjoy a few cervezas (although in my opinion Mexican beer, especially the imported one here is the USA are average at best) I would suggest Modelo, Tecate. Corona or Dos Equis. Also no lime...but that is a post for later.
Toast the brave fighters who fought and won (at least for a year) defending their Country against a superior invading force.
Now that we know the real story. Happy Cinco De Mayo