He Flag of Mexico is rich with historical symbolism. The tricolors of white, green and red with the coat-of-arms centered in the white middle stripe were adopted by Mexico after their independence from Spain during the War of Independence in 1821.
There have been adjustments to the flag throughout background but the coat of arms has ever featured a royal eagle holding a serpent in addition to a cactus. The present coat of arms was created in 1968 by Helguera. Legend claims that the Aztecs, then a nomadic tribe wandering throughout Mexico, were awaiting a sign from the gods telling them to build their own capital city. After drifting for two hundred years, they found this mythical eagle on a little island in Lake Texcoco and built their capital, Tenochtitlan, where the most important plaza in Mexico City is now located.
Through time the three colors of white, green and red on the flag have remained the same but the meaning of these colours has changed. The green stripe represents Independence from Spain or may signify Hope. The white stripe represents purity of the Catholic religion or Unity.
After the flag of Mexico is paraded in front of a crowd, bystanders increase their right arm, put their hands on their chest parallel to the center. The hand is level with the palm facing the floor. This salute is referred to as the El Saludo Civil de la Bandera Nacional. On February 24 annually a nationwide party, Dia de la Bandera, Flag Day is held.