Mexico, officially the United Mexican States, was founded as an independent country in 1821. Before the Spanish conquest in the 16th century, it was home to numerous complex systems of native civilizations, with ancestry reaching back to 20,000 B.C.
The name Mexico has its origins in the Aztec language, though this name was not used to describe the whole region until much later. As a part of the Spanish Empire, Mexico was known as New Spain, along with most of Central America and parts of North America. Modern-day Mexico is a federal republic composed of 31 states and one Federal District, Mexico City.