Mexican Independence Day is September 16 and it originated in 1810. Mexican Independence Day is nowhere near Cinco De Mayo, which is on May 5, and originated in 1862.
It was actually a celebration of the victory at the Battle at Pueblo.
To make a long story short, the France were trying to take an opportunity to strike while the iron was hot because Mexico was in a time of financial ruin. Napoleon III sent 6,000 French troops to Pueblo de Los Angelos. The President of Mexico at the time, Benito Juárez, sent “a ragtag force of 2,000 loyal men—many of them either indigenous Mexicans or of mixed ancestry—to fight the French.”
The battle lasted took place entirely under the sun and after and after the French lost 500 men, they retreated. This was impressive because Mexico had only lost around 100 men.
Although this was not a HUGE victory, this victory paved the way for many victories in the Mexican futures.
What was once a Mexican small celebration in Pueblo, is now a huge cultural event all across American.
This is Cinco De Mayo.