Mexico, officially the United Mexican States
, is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of Mexico. Covering almost two million square kilometres, Mexico is the fifth largest country in the Americas by total area and the 13th largest independent nation in the world. With an estimated population of over 113 million, it is the eleventh most populous and the most populous Spanish-speaking country in the world and the second most populous country in Latin America. Mexico is a federation comprising thirty-one states and a Federal District, the capital city.
In pre-Columbian Mexico many cultures matured into advanced civilizations such as the Olmec, the Toltec, the Teotihuacan, the Zapotec, the Maya and the Aztec before first contact with Europeans. In 1521, the Spanish Empire conquered and colonized the territory from its base in México Tenochtitlan, which was administered as the Viceroyalty of New Spain. This territory would eventually become Mexico following recognition of the colony's independence in 1821. The post-independence period was characterized by economic instability, the Mexican-American War that led to the territorial cession to the United States, the Pastry War, the Franco-Mexican War, a civil war, two empires and a domestic dictatorship. The latter led to the Mexican