It may occur to you to wonder what would inspire a culture like Mexico's to create a fiesta (or festival) called Cinco de Mayo (or Fifth of Mayo), dedicated to Mayo (or as it is more properly known,
Mayonnaise: an oily emulsion of oil, egg, vinegar, and perhaps lemon or seasonings). This now ever-popular celebration comes every spring; and so as not to conflict with its northern neighbor's holidays (the United States of America), was placed between the U.S. Mother's Day and Father's Day, and well ahead of the U.S. Independence Day. The Mexico Independence Day is September 16 (1821), so it helped balance things out a bit by occupying the period between Easter and then.
This now-sacred day commemorates the victory of the Mexican people over the French at 'The Battle of Puebla' (War of the Bottle or Jar) in 1862. This, then, is its story.
Setting the table
The Mexican-American War was still strong in the memories of the people. It had been a draining incident, resulting in the loss of much of the output of the Mexican salsa mines and underground Tequila reservoirs. The subsequent Mexican Civil War in 1958 managed to destroy the Mexican economy even further. They owed some big bills, to the big players of the time - Spain, England and France - using their country as collateral, and found themselves in drastic need of debt counseling.
Debt counseling, unfortunately, had not yet been invented so they were forced to stop making payments, instead claiming that the check was in the mail. France chose to create the world's first debt-counseling plan, on Mexico's behalf, and repossess the country.
Spain and England backed off, whilst France attempted to send a military leader from Austria to take possession of this middle-America gem. Their plan was to force the Mexicans to purchase high quotas of Mayonnaise in one-fifth of a French Imperial Gallon (FIG) jars, padded with taxes and import/export fees, until the Mexican economy completely folded, and the salsa mines ran completely dry. They could then take the country without firing a shot.
The first hints at dissatisfaction, and of Mexico's recognition of France's devious plan, appeared in the form of the great 'Cancun
Mayonnaise Fiesta', or grande 'Cancun Mayo Party' (an obvious attempt at leveraging the successful tea party idea used in Boston, Massachussettettetts, USA), in which cases containing many fifths of mayonnaise were hurled from the docking French merchant boats into the waters connecting the Gulf of Mexico and the Caribbean Sea.
In any case, mayo simply does not travel well, which you would know if you ever got hold of mayo gone bad; which is how the peninsula got the name 'Yuckatan Peninsula' (later shortened to Yucatan).
[An interesting side note: Oil and water do not mix well, and oil floats; so, most of the cases simply bobbed about a bit until an enterprising Mexican rabble-rouser tried sinking them using shot. Unfortunately, released mayo does not sink either. The local fish, unable to get replenishing oxygen, tended to float to the surface where the mayo - seasoned with seaweed - floated, creating a sort of tartar sauce. The upshot was that he created the worlds first, all "you can eat fish fry", for which he got neither credit nor a percentage of the profits.]
In response, the French sent troops to Vera Cruz with instructions to 'make them sorry they insulted our mayonnaise!' The expectations were that the troops would get drunk, rowdy, and randy and generally cause great pressure on the Mexican government. The French general misread the instructions and began a 600 mile march to Mexico City, Mexico's capital.
Mexico turned to the United States for aid, but U.S. President Abraham Lincoln made some lame excuse about being busy with some internal issues at the time - something to do with a supposed 'Civil War'. Abraham asked his general U.S. Grant to swing by; but by the time Grant's men arrived the French had left. Not wanting the trip to be a complete waste, Grant and his men burned some fields and destroyed a few buildings before returning home.
Miraculously, the Mexicans were able to defeat the sophisticated, well-outfitted, French army of 6,500 drunken soldiers with a militia of a mere 4,500 men (the famous 'Fifth Battalion', later christened 'Cinco de Mayo') by turning the French's own weapon against them. They ringed the city with a river of spoiled mayonnaise. Even the French were powerless against the stench of so much mayo left out in the sun for days.
By hurling goats' bladders and fifths filled with the vile substance, the Mexican troops routed the French and retook the country. Unfortunately, the Mexicans had run out of mayo by the time Napoleon sent more than 30,000 drunken French troops the next year, who just walked in and grabbed the whole thing.
Things seemed stable for about three years, until the U.S. decided to stick their collective nose into things. The 'liberation' of Mexico still causes confusion to this day, as many Mexicans believe that the U.S. wants Mexican farm workers as much as they want Mexico's high-grade salsa.