Treaty of Córdoba
The Treaty of Córdoba established Mexican independence from Spain at the conclusion of the Mexican War of Independence. It was signed on August 24, 1821 in Córdoba, Veracruz, Mexico. The signatories were the head of the Army of the Three Guarantees, Agustín de Iturbide, and, acting on behalf of the Spanish government, "Jefe Político Superior" Juan O'Donojú. The treaty has 17 articles, which developed the proposals of the Plan of Iguala. The Treaty is the first document in which Spanish (without authorization) and Mexican officials accept the liberty of what will become the First Mexican Empire, but it is not today recognized as the foundational moment, since these ideas are often attributed to the Grito de Dolores (September 16, 1810). The treaty was rejected by the Spanish government. Spain did not recognize Mexico's independence until December 1836.
Puebla
Cinco de Mayo—or the fifth of May—is a holiday that celebrates the date of the Mexican army's 1862 victory over France at the Battle of Puebla during the Franco-Mexican War (1861-1867). A relatively minor holiday in Mexico, in the United States Cinco de Mayo has evolved into a commemoration of Mexican culture and heritage, particularly in areas with large Mexican-American populations. 
Many Americans mistakenly believe that Cinco de Mayo (“May 5th”) is the Mexican equivalent of the United States’ Fourth of July holiday — a date marking the official casting off of colonial rule via the announcement of a new independent country. However, the Mexican version of Independence Day is celebrated on September 16, for it was on that date in 1810 that the commencement of the war for Mexican independence from Spanish rule was pronounced in the small town of Dolores by Miguel Hidalgo y Costilla (an event now referred to as the “Grito de Dolores” — “Cry of Dolores” — or “El Grito de la Independencia”).