So what is Cinco de Mayo? It's a holiday that celebrates the victory of the Mexican army over the French army on May 5, 1862, at the Battle of Puebla. Led by General Ignacio Zaragoza Seguín, the poorly equipped Mexican army made a stand against French forces near the forts of Loreto and Guadalupe. Even though the French had more soldiers—about 8,000 men to the Mexicans' 4,000—the Mexican army won. People thought the French army was the best in the world at the time and had not lost a battle in nearly 50 years. This victory became a source of pride for the Mexican people.
While the victory was short-lived—the French later captured Mexico City and took over the country—it stood for a moral victory for the Mexican government. It became a symbol of unity and pride for people who were supposed to lose a battle. Today, Cinco de Mayo is not that important in Mexico. They mainly celebrate it in the state of Puebla. In Mexico, they honor Independence Day on September 16, which is the nation's most important national holiday.
Sourced from Wonderopolis