Mexican War of Independence recognized Mexican independence under the Plan of Iguala. On September 27, 1821 the Army of the Three Guarantees entered Mexico City, and the following day Iturbide proclaimed the independence of the Mexican Empire, as New Spain was henceforth to be called. The Treaty of Córdoba was not ratified by the Spanish Cortes. Iturbide included a special clause in the treaty that left open the possibility for a criollo monarch to be appointed by a Mexican congress if no suitable member of the European royalty would accept the Mexican crown. Half of the new government employees appointed were Iturbide's followers. On
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