New Spain Spain, at 42d north (now the northern boundary of the U.S. states of California, Nevada, and Utah). In the 1821 Declaration of Independence of the Mexican Empire, both Mexico and Central America declared their independence after three centuries of Spanish rule and formed the First Mexican Empire, although Central America quickly rejected the union. After priest Miguel Hidalgo y Costilla's 1810 Grito de Dolores (call for independence), the insurgent army began an eleven-year war. At first, the Criollo class fought against the rebels. But in 1820, a military coup in Spain forced Ferdinand VII to accept the authority of the
Mexican War of Independence of Iguala, Iturbide persuaded Guerrero to join his forces in support of this conservative independence movement. A new army, the Army of the Three Guarantees, was placed under Iturbide's command to enforce the Plan of Iguala. The plan was so broadly based that it pleased both patriots and loyalists. The goal of independence and the protection of Roman Catholicism brought together all factions. Iturbide's army was joined by rebel forces from all over Mexico. When the rebels' victory became certain, the Viceroy resigned. On August 24, 1821, representatives of the Spanish crown and Iturbide signed the Treaty of Córdoba, which