Many Americans believe Cinco de Mayo marks the anniversary of Mexican Independence from Spain, but nothing could be further from the truth, although marketing executives on both sides of the border are happy to let the misconception soar in the popular imagination so long as alcohol and party sales remain high.  It’s fitting to explain the reality behind the celebration of Cinco de Mayo.  The day has significant meaning for every American and ought to be recognized for the service our neighbors to the south performed for themselves and, by extension, for us.
Mexico was badly disorganized and very broke after the United States had conquered half its territory in 1848.  Borrowing heavily from the Catholic church to finance its lost war, and suffering the loss of trade with the rest of the world, Mexico was in debt and was doubtful of its safety.  Meanwhile, European nations were loath to invest in what they believed would soon be another part of the United States.  Trade with Europe was scant and merely increased the debts Mexicans owed the French, Spanish and British who began to recoup their debts by sending a combined force of soldiers to occupy the Gulf ports of Mexico and take over the customs houses to skim off fees and duties from imports.
After the usual shows of force, the high-level squabbling between diplomats and the negotiations for repayment, the British and Spanish withdrew their soldiers.  The French did not.  Napoleon III, Emperor of France, had ambitions to pick up the American empire which his famed ancestor got rid of 60 years earlier.  France needed resources to successfully challenge the British empire.  Putting a French foot on other European nations trying to assert themselves would take more resources than France had at home; France needed an American empire and Mexico was to be its first base of operations.
French ambitions were fed by the American Civil War that was still going strong.  The American Monroe Doctrine warned all nations not to extend any hooks into either American continent unless they wanted a war with the United States.  But war between the states meant American forces couldn’t interfere with imperial land grabs.  Mexico was weak.  The US was preoccupied with a civil war and the French, under Napoleon III, needed immediately to grab what they could get from the Mexicans.
The French also had a long-term plan to demolish US power by siding with the Confederacy when the time was right, after the French got a strong foothold in Mexico.  Once that foothold was solid, aid to the Confederates would help the South gain its independence and would make them subservient pawns to French power brokers.  Even better, a Confederate-French victory over the US would mean the end of the United States as a power capable of thwarting European expansion.  For France, it meant a chance to reassert itself on the American continent for the first time since losing the French and Indian War in 1763.  For France, winning Mexico was intended to be the first step toward becoming the dominant power on earth.
A French army commanded by General Laurencez began to march from Veracruz to Mexico City.  When it got to Puebla, a village about 100 miles from the capital it found a force of about 4,000 Mexicans waiting for them.  Those Mexicans were mostly agricultural workers and peasants armed with ancient British flintlocks and machetes.  The 6,000 man French army, regarded, in those days, as the most dangerous on earth, came equipped with cavalry, artillery and strategic precision.  Their rifles could hit a man at almost twice the range of the Mexican weapons and their tactical skill was flawless.
The Mexican commander, Ignacio Zaragoza, was shrewd enough to make sure the coming battle would take place on favorable ground, a muddy, uneven field that allowed his few soldiers on unshod ponies a decent chance against the heavily equipped French cavalry.  He learned to give his horsemen some advantages, after he lost the first engagement to the French cavalry on April 28, when the French had cut his lightly armed riders to pieces.  Zaragoza was a quick learner and between the day his cavalry was shredded and May 5, he thought up tactics to minimize the French advantages at Puebla.
Laurencez accommodated Zaragoza by attacking at the Mexicans’ strongest point, after a late start which gave Zaragoza time to prepare better defenses.  Laurencez sent his cavalry through ditches and mud uphill where they became quickly bogged down and were drawn off the field chasing after the Mexican horsemen.  The French artillery then opened fire and battered Puebla and the Mexicans in the town; Zaragoza gritted his teeth and told his countrymen to endure it and wait until the right moment came.  All the while, the French infantry advanced toward them, struggling in the mud, which only got worse when it began to rain.
When the French artillery ran out of ammunition, the bulk of the French infantry advanced on Puebla and were shot at merrily by Mexicans who had held fire until the French were in range.  The last French infantry attack was broken up imaginatively by Mexican peasants who stampeded their cattle at the French formations.  Each steer weighed about a ton.  And hundreds of angry steers coming at the long line of French infantry routed them in panic.  At the end of the day, Laurencez had lost 462 men to Mexico’s 83.  Laurencez couldn’t get past Puebla to Mexico City.  After waiting for Zaragoza to attack or run, Laurencez had to move all the way back to Orizaba, in the wrong direction and away from Mexico City.
The war wasn’t won that day, of course.  It dragged on for several more years and, until 1867, the French sat a puppet king on a Mexican throne.  But Puebla was important because it stopped the French advance when it did and it bought Mexico another whole year to organize and fight before the French took their capital.  It also bought a year for the United States and that was critical.  Napoleon III’s plan to conquer Mexico depended on a weak United States and a Confederacy strong enough to stand on its own with French help.  Losing time by failing to consolidate their Mexican base, the French in effect gave time to the Mexicans to organize and to the US who then beat the Confederates at Gettysburg and showed Napoleon III that the South lacked enough force to be an equal partner in a combined alliance with France.
The French plan had a fine logic to it: establish a power base made of French soldiery and capital, Mexican landowners and the Catholic church, aid the Confederates and move north to split the US in two and possibly reclaim the lost Louisiana territory.  Had Laurencez won the day, on May 5, 1862, the French would have been able to carry out their strategy when the US was at its weakest point against the Confederacy.  If the US had to face a southern army equipped with French artillery and other weapons, backed by a French navy guarding blockade runners bringing war supplies to the south, the north may have lost the war and the country with it.  The US strategy depended on strangling the south’s supplies until they couldn’t continue fighting.
So, the Mexican victory over the French at Puebla is really a Union Civil War victory bought for Uncle Sam by a leader of a Mexican peasant army that took a beating and stampeded its cattle at some of the finest troops on the planet.  So on May 5, be sure to hoist a Cerveza, and maybe some Tequila, in honor of those who helped save our nation.  God knows, they earned the toast.