Mexican War of Independence 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. The movement for
Mexican–American War could not be released from its obligations. The US was released from all obligations of Article XI five years later by Article II of the Gadsden Purchase of 1853. The 1848 Treaty of Guadalupe Hidalgo ended the war and enforced the Mexican Cession of the northern territories of Alta California and Santa Fe de Nuevo México to the United States. Mexico acknowledged the loss of what became the State of Texas and accepted the Rio Grande as its northern border with the U.S. The losses amounted to one-third of its original territory from its 1821 independence. Before the secession of