Mexican War of Independence
The Mexican War of Independence () was an armed conflict, and the culmination of a political and social process which ended the rule of Spain in 1821 in the territory of New Spain. The war had its antecedent in Napoleon's French invasion of Spain in 1808; it extended from the Cry of Dolores by Father Miguel Hidalgo y Costilla on September 16, 1810, to the entrance of the Army of the Three Guarantees led by Agustín de Iturbide to Mexico City on September 27, 1821. September 16 is celebrated as Mexican Independence Day.
Republic of the Rio Grande
After a decade of strife, Mexico won its independence from the Kingdom of Spain in 1821. After a failed attempt at a monarchy, Mexico adopted a new constitution, the 1824 Constitution. This new constitution established los "Estados Unidos Mexicanos", or "the United Mexican States," as a federal republic. During the war for independence, many rebels were driven to Coahuila and Nuevo León, where this revolutionary mentality won the hearts and minds of the people.