The written history of Mexico spans more than three millennia. First populated more than 13,000 years ago,[1] central and southern Mexico (termed Mesoamerica) saw the rise and fall of complex indigenous civilizations. Mexico would later develop into a unique multicultural society. Mesoamerican civilizations developed glyphic writing systems, recording the political history of conquests and rulers. Mesoamerican history prior to European arrival is called the prehispanic era or the pre-Columbian era. Following Mexico's independence from Spain in 1821, political turmoil wracked the nation. France, with the help of Mexican conservatives, seized control in the 1860s during the Second Mexican Empire, but was later defeated. Quiet prosperous growth was characteristic in the late 19th century but the Mexican Revolution in 1910 brought a bitter civil war. With calm restored in the 1920s, economic growth was steady while population growth was rapid.
The conquest of Mexico was followed by colonization by the Spaniards. The conquerors imposed the Spanish government and the Roman Catholic religion on the indigenous peoples of Mexico. Thousands of Spaniards immigrated into Mexico. The Spanish rulers gradually took control of the land, wealth and labor of the country.
The presence of people in Mesoamerica was once thought to date back 40,000 years, an estimate based on what were believed to be ancient footprints discovered in the Valley of Mexico; but after further investigation using radiocarbon dating, it appears this date may not be accurate. It is currently unclear whether 23,000-year-old campfire remains found in the Valley of Mexico are the earliest human remains uncovered so far in Mexico. The first people to settle in Mexico encountered a climate far milder than the current one. In particular, the Valley of Mexico contained several large paleo-lakes (known collectively as Lake Texcoco) surrounded by dense forest. Deer were found in this area, but most fauna were small land animals and fish and other lacustrine animals were found in the lake region. Such conditions encouraged the initial pursuit of a hunter-gatherer existence. Indigenous peoples in western Mexico began to selectively breed maize (Zea mays) plants from precursor grasses (e.g., teosinte) between 5,000 and 10,000 years ago. The diet of ancient central and southern Mexico was varied, including domesticated corn (or maize), squashes such as pumpkin and butternut squash, common beans (pinto, kidney, navy and other common beans consumed today), tomatoes, peppers, cassavas, pineapples, chocolate, and tobacco. The Three Sisters (corn, squash, and beans) constituted the principal diet.
