The Mexican-American societies were formed after the Mexican-American war (1846-1848) in response to atrocities committed by US. troops occupying the lands annexed by the US. following the war. The war was settled by the Treaty of Guadalupe Hidalgo with fifteen million dollars in payment for the annexed lands. The societies originally consisted of home guard units but evolved into social societies as stability returned to the US Southwest. These societies contributed large amounts of material and money to the Mexican Constitutional Government in its fight against the Mexican Imperial Monarchy.

In 1858, Benito Juárez was elected President of the United States of Mexico to defend the Mexican Constitution established on February 5th, 1857. After much internal struggle, Juárez was re-elected in 1861. Because of financial instability, mainly due to the Mexican-American war, the Mexican Congress suspended foreign debt repayment for two years.

The creditors in Europe (England, Spain and France) decided intervention was needed to collect the debts. Unbeknownst to the other two, France had its own agenda. France wanted to dispose of the Mexican Constitutional Government and set up a monarchy favorable to France. Napoleon III, Emperor of the Second French Empire had grandiose plans to impose a monarchical government upon the nations of Central and South America. This was to provide raw materials and trade for the European nations as well as check the growing power of the US Republic following the annexation of California, Arizona and New Mexico.

France's designs were formented and abetted by the plutocratic and conservative land owners of Mexico who feared loss of land and political power to the newly elected constitutional government of Benito Juárez. On December 8th, 1861 the European powers landed and occupied Veracruz, Spain arrived first. By April 11, 1862 after realizing France's intent, England and Spain withdrew their support.

Meanwhile, in Mexico City, President Juárez (a full blooded Zapotec Indian, and a lawyer who had studied to become a priest), was taking countermeasures: "There is no help but in defense but I can assure you... the Imperial Government will not succeed in subduing the Mexicans, and its armies will not have a single day of peace... we must stop them, not only for our country but for the respect of the sovereignty of the nations"(1). Juarez declared martial law and declared all areas occupied by the French in a state of siege.

After reinforcements arrived, a French force of (7,000) seven thousand set out on the (225) two hundred twenty five mile route to Mexico City in early April under the illusion that the Mexican people would welcome them. This illusion was fostered by Juan N. Almonte, a Mexican reactionary, and by Count Dubois du Saligny appointed French Ambassador to Mexico by Napoleon. Presidente Juárez commanded General Ignacio Zaragoza to block the advance of the French Army with 2,000 soldiers at the fortified hills of Loreto and Guadalupe by the city of Puebla.

On May 5th, 1862, cannons boomed and rifle shots rang out as the French soldiers attacked the two forts. Before the day was over, one fort was in ruins and more than a thousand French soldiers were dead. The Mexicans had won the battle, but not the war. Yet, this date was established as symbolic of the Mexicans' courage against a formidable army.

In June 1864, Maximilian of Habsburg and his wife Charlotte arrived in Mexico City as the crowned Emperor of the newly formed Mexican Empire. Although Maximilian organized the administration, liberated the Indians from servitude, and developed the natural resources of the country, he was unable to avoid the opposition of the Mexican patriots. The republicans, led by Benito Juárez, did not accept the foreign intervention. They went north and requested assistance from the Californians and other Mexican-American societies to help them with volunteers and financial support.

Finally, Maximilian was overthrown and captured on May 15, 1867, tried by court martial, and executed by firing squad on June 19 at the Cerro de las Campanas along with his generals Miguel Miramón and Tomás Mejía.

The 5 de Mayo is a Mexican national holiday. The battlefield is now a park in Puebla with a statue of General Zaragoza riding horseback. One of the forts is a war museum with a display of hundreds of toy soldiers set up to show what had happened that day. But it is in the United States of America where the celebration is more festive consisting of parades, music, folklore, dances and food. These festivities are mainly fund raising events and for solidarity among the Mexican-Americans.