The first Mexican flag is the same as the national flag you see at present. However, the eagle that has a crown used to lack the serpent that it now devours and grips tightly with its sharp talons.
The second national flag of the country was raised in the beginning of the first federal republic in 1823. The only difference with the new flag was that the coat of arms was replaced. The crown on the eagle was taken out and a serpent was added to the right talon. There was also a branch of oak and laurel featured on the banner. The flag was removed in 1864 after the federal republic was also taken down.
Next is the national flag showing the green, red and white pattern, together with the coat of arms at the center on the white stripe. The length of the flag has changed from 4:7 to 1:2 and there were four golden crowned eagles placed on each of the four corners. The design was ordered in 1864 by the Emperor Maximilian, inspired by his French taste. The flag was again removed in 1867 when the emperor was ousted by the Mexicans.
Next was the flag with the lone eagle and serpent again, but without a crown. It was raised frequently but was not yet the official national flag.
The present Flag of Mexico was officially adopted on September 16, 1968. The eagle was transformed to face the side instead of the front.
Mexico City also became host to the 1968 Olympic Games during the summer, which resulted to a new Mexican flag.