Some people think Cinco de Mayo is Mexican Independence day. The date Cinco de Mayo represents happened 40 years after independence from Spain.
September 16, 1810, was the day the revolution began. Mexico did not gain independence from Spain until September 27, 1821. However, the day they celebrate is September 16, El Grito de Dolores. Literally translated this means the Shout of Pain. This is wrong. Dolores was the name of the town where Miguel Hidalgo was about to be arrested for planning a revolt. Instead of waiting for them to come take him away, he rang the church bells and rallied the townspeople into taking up arms then and there. This was the spark that spread across Mexico to eventually end in independence.