The flag of Mexico was developed in 1821, the year in which Mexico became independent from Spain. The flag has changed several times since 1821, with the most recent design adopted in 1968. From the beginning it has had three vertical stripes in green, white and red, as these were the colors of the National Liberation Army of Mexico. In addition, there is the symbol of an eagle that appears in the middle of the white stripe.

The emblem of the eagle is based on the Aztec legend of the discovery of Tenochtitlan, the ancient Aztec capital now known as Mexico City. It is said that the Aztecs saw an eagle sitting on a cactus, known as a nopal, while eating a snake and took it as a sign of where to found their city. The Aztecs arrived in this area in 1325, and in 1519, when the Spaniards arrived, there were some 400,000 people living there. The lake of Texcoco, near the city of Tenochtitlan, is also represented below the cactus in the emblem.

The Aztecs spoke an indigenous language known as Nahuatl. This language is still alive in many words in Spanish, some of which have been borrowed into English. The following are some examples: coyote, guacamole, chocolate, chia and tomato. Nahuatl is still spoken today by an estimated 1.5 million people in Mexico.