exican Empire", which recognized the independence of Mexico under the terms of the "Plan of Iguala".
Juárez reforms and territorial losses
Agustín de Iturbide immediately proclaimed himself emperor of the First Mexican Empire. A revolt against him in 1823 established the United Mexican States. In 1824, a Republican Constitution was drafted and Guadalupe Victoria became the first president of the newly born country. The first decades of the post-independence period were marked by economic instability, which led to the Pastry War in 1836, and a constant strife between liberales, supporters of a federal form of government, and conservadores, proposals of a hierarchical form of government.
General Antonio López de Santa Anna, a centralist and two-time dictator, approved the Siete Leyes in 1836, a radical amendment that institutionalized the centralized form of government. When he suspended the 1824 Constitution, civil war spread across the country, and three new governments declared independence: the Republic of Texas, the Republic of the Rio Grande and the Republic of Yucatán.
Texas successfully achieved independence and was annexed by the United States. A border dispute led to the Mexican-American War, which began in 1846 and lasted for two years; the War was settled via the Treaty of Guadalupe Hidalgo, which forced Mexico to give up over half of its land to the U.S., including Alta California, New Mexico, and the disputed parts of Texas. A much smaller transfer of territory in what is today southern Arizona and southwestern New Mexico — the Gadsden Purchase — occurred in 1854. The Caste War of Yucatán, the Mayan uprising that began in 1847, was one of the most successful modern Native American revolts. Maya rebels, or Cruzob, maintained relatively independent enclaves until the 1930s.
Dissatisfaction with Santa Anna's return to power led to the liberal "Plan of Ayutla", initiating an era known as La Reforma, after