citizens. Mexico acknowledged the loss of their province, later the Republic of Texas (and now the State of Texas), and thereafter cited and acknowledged the Rio Grande as its future northern national border with the United States. Including Texas, Mexico ceded an area of approximately – by its terms, around 55% of its former national territory. Mexico The 1840s for Mexico were the end of the centralist government and the waning years the "Age of Santa Anna". In 1834, President Antonio López de Santa Anna dissolved Congress, forming a new government. That government instituted the new Centralist Republic of Mexico by approving a new centralist constitution ("Siete Leyes"), From its formation in 1835 until its dissolution in 1846, the Centralist Republic was governed by eleven presidents (none of which finished their term). It called for the state militias to disarm, but many states resisted, including Mexican Texas, which won its independence in the Texas Revolution of 1836. The Republic of the Rio Grande declared its independence from Mexico in January 1840. However, the border with Texas was never determined (whether the Nueces River or the Rio Grande). The new Republic fought a brief and unsuccessful war for independence, returning to Mexico late in the year. In 1841, Generals Santa Anna and Paredes led a rebellion against President Bustamante, resulting in Santa Anna becoming president of the centralist government for a fifth time . Local officials in Yucatán declared independence in 1841, opposing strong autocratic rule and demanding the restoration of the Constitution of 1824, thus establishing the second Republic of Yucatán. In 1842, the region of Soconusco was annexed by Mexico as part of the state of Chiapas, following the dissolution of the Federal Republic of Central America. In 1846, President Paredes and the Congress of Mexico declared war at the beginning of the Mexican–American War. Paredes' presidential successor was deposed in a coup, replaced by José Mariano Salas. Salas issued a new decree that restored the Constitution of 1824, ending the Centralist Republic and beginning the Second Federal Republic of Mexico. After the conclusion of the Mexican–American War, José Joaquín de Herrera became the second president of Mexico to finish his term (Mexico's first president completed his in 1829). It was during this time that Yucatán reunited with Mexico. A decisive factor for the reunion was the Caste War of Yucatán (a revolt by the indigenous Maya population) for