Since the colonial era and up to the 21st century, the indigenous roots of Mexican history and culture have been important to Mexican identity. The National Museum of Anthropology in Mexico City is a showcase of the country's pre-Hispanic greatness. Although the Spanish Empire established colonies in the Caribbean starting in 1493, it was not until the second decade of the sixteenth century that they began exploring the eastern coast of Mexico. Spaniards first learned about Mexico during the expedition of Juan de Grijalva in 1518. The Spanish conquest of the Aztec Empire began in February 1519, when Hernan Cortez landed on the Gulf coast and founded the Spanish city of Veracruz. About 500 conquistadors, along with horses, cannons, swords and long guns, gave the Spaniards some technological advantages over local warriors, but the key to Spain's victory was the conclusion of strategic alliances with disaffected local city-states (Altepetl), who fought with them against the Triple Alliance of the Aztecs. Also an important role in the victory of Spain was played by the cultural translator Cortez Malinche, a Nahua woman enslaved in the Maya area, which the Spaniards purchased as a gift. She quickly learned Spanish and gave strategic advice on how to deal with both allies and enemies from the indigenous population.
The capture of Tenochtitlan in 1521 and the immediate foundation of the Spanish capital Mexico City on its ruins marked the beginning of a 300-year colonial era during which Mexico was known as New Spain. Two factors made Mexico the jewel of the Spanish Empire: the existence of a large, hierarchically organized Mesoamerican population that paid tribute and performed compulsory labor, and the discovery of extensive silver deposits in northern Mexico. The Kingdom of New Spain was created from the remnants of the Aztec Empire. The two pillars of Spanish rule were the state and the Roman Catholic Church, both under the rule of the Spanish crown. In 1493, the Pope granted the Spanish monarchy broad powers for its overseas empire on the condition that the crown would spread Christianity in its new kingdoms. In 1524, King Charles I created the Council of the Indies, based in Spain, to oversee state power in its overseas territories; in New Spain, the Crown established a high court in Mexico City, a real Audiencia, and then in 1535 established the Viceroyalty of New Spain. The Viceroy was the highest official of the State. In the religious sphere, the Diocese of Mexico was established in 1530 and elevated to the Archdiocese of Mexico in 1546, with the archbishop as the head of the church hierarchy overseeing the Roman Catholic clergy. Castilian Spanish was the language of the rulers. The Catholic faith was the only one allowed, non-Catholics (Jews and Protestants) and Catholics (with the exception of Indians) who held unorthodox views were subject to the Mexican Inquisition, founded in 1571.
In the first half century of Spanish rule, a network of Spanish cities was created, sometimes in pre-Columbian territories where a dense indigenous population lived. The capital of Mexico City was and remains the main city, but other cities founded in the sixteenth century remain important, including Puebla, Guadalajara and the port of Veracruz. Cities and towns were centers of civil officials, clergy, business, the Spanish elite, as well as artisans and workers of mixed race and indigenous peoples. The viceroyalty to the greatest extent included the territories of modern Mexico, Central America up to Costa Rica in the south and western part of the USA. The capital of the viceroyalty of Mexico City also ruled the Spanish West Indies (Caribbean), the Spanish East Indies (Philippines) and Spanish Florida. In 1819, Spain signed the Adams-Onis Treaty with the United States, which established the northern border of New Spain.
The rich deposits of silver, especially in Zacatecas and Guanajuato, led to the fact that silver mining became dominant in the economy of New Spain. The Mexican silver peso became the first currency used worldwide. Taxes on the production of silver became the main source of income for the Spanish monarchy. Other important industries were agriculture and cattle haciendas, as well as trading activities in the main cities and ports. Thanks to trade links with Asia, the rest of America, Africa and Europe, as well as the profound influence of New World silver, Central Mexico became one of the first regions to be included in the globalized economy. Being at the crossroads of trade, people and cultures, Mexico City is called "the first city in the world". The Nao de China (Manila galleons) were operated for two and a half centuries and connected New Spain with Asia. Silver and cochineal red dye were shipped from Veracruz to the Atlantic ports of North and South America and Spain. Veracruz was also the main port of entry into the mainland of New Spain of European goods, immigrants from Spain and African slaves. The Camino Real de Tierra Adentro connected Mexico City with the interior of New Spain.
The population of Mexico was overwhelmingly indigenous and rural throughout the colonial period and beyond, despite a significant reduction in their numbers due to epidemic diseases. Diseases such as smallpox, measles and others were introduced by Europeans and African slaves, especially in the sixteenth century. The indigenous population stabilized at one to one and a half million people in the 17th century, compared with the most common figure of five to thirty million people before contact was established. During the three hundred years of the colonial era, Mexico received from 400 to 500 thousand Europeans, from 200 to 250 thousand African slaves and from 40 to 120 thousand Asians.
Under Viceroy Revillagigedo, the first comprehensive census with racial classifications was conducted in 1793. Although most of her original datasets have reportedly been lost, thus much of what is known about her comes from essays and field studies conducted by scientists who had access to census data and used them as reference materials for their work, such as the German scientist Alexander von Humboldt. Europeans made up from 18% to 22% of the population of New Spain, Mestizos – from 21% to 25%, Indians – from 51% to 61%, and Africans – from 6,000 to 10,000 people. The total population ranged from 3,799,561 to 6,122,354. It is concluded that the growth trends in the number of whites and mestizos were uniform, while the percentage of the indigenous population decreased at a rate of 13-17% per century, mainly due to the fact that the latter had higher mortality rates due to living in remote areas and constant war with colonists.
Colonial law with Spanish roots was introduced and secured to local customs, creating a hierarchy between the local jurisdiction (cabildos) and the Spanish crown. The highest administrative positions were closed to natives of the country, even those in whose veins flowed pure Spanish blood (criollos). The administration was based on racial division. Society was organized according to a racial hierarchy, with whites at the top, mixed-race people and blacks in the middle, and indigenous people at the very bottom. There were official legal designations of racial categories. The Republic of Spaniards (Republic of Spain) consisted of Spaniards of European and American descent, Castes of mixed race and black Africans. The Republic of the Indians (República de Indios) consisted of an indigenous population, which the Spaniards united under the term "Indians" (indio), a Spanish colonial social construct that indigenous groups and individuals rejected as a category. Spaniards were exempt from paying tribute, Spanish men had access to higher education, could hold civil and ecclesiastical positions, were subject to inquisition and conscription when permanent armed forces were created at the end of the eighteenth century. Indigenous peoples paid tribute but were exempted from the Inquisition, indigenous men were excluded from the priesthood; and exempted from military service. Although the racial system seems immutable and inflexible, there was some mobility in it, and the racial dominance of whites was not complete. Since the indigenous population of New Spain was very large, the demand for expensive black slaves was less than in other parts of Spanish America. At the end of the eighteenth century, the crown carried out reforms that granted the Spaniards (peninsulares) of Iberian origin privileges over the natives of America (criollos), limiting their access to official positions. This discrimination between the two of them caused discontent among the white elite in the colony.