Mexican War of Independence
Although Mexico gained its independence in September 1821, the marking of this historical event did not take hold immediately. The choice of date to celebrate was problematic, because Iturbide, who achieved independence from Spain, was rapidly created Emperor of Mexico. His short-lived reign from 1821–22 ended when he was forced by the military to abdicate. This was a rocky start for the new nation, which made celebrating independence on the anniversary of Iturbide's Army of the Three Guarantees marching into Mexico City in triumph a less than perfect day for those who had opposed him. Celebrations of independence during his reign were marked on September 27. Following his ouster, there were calls to commemorate Mexican independence along the lines that the United States celebrated in grand style its Independence Day on July 4. The creation of a committee of powerful men to mark independence celebrations, the "Junta Patriótica", organized celebrations of both September 16, to commemorate Hidalgo's grito and the start of the independence insurgency, and September 27, to celebrate actual political independence.
History of Mexico
By 1823, Mexicans of all classes were fed up with emperor Agustin de Iturbide's corrupt and oppressive rule. They overthrew him and 4 October 1824, the United Mexican States (Spanish: Estados Unidos Mexicanos) was established. The new constitution was partly modeled on the constitution of the United States. It guaranteed basic human rights and defined Mexico as a representative federal republic, in which responsibilities of government were divided between a central government and a number of smaller units called states. It also defined Catholicism as the official and unique religion. The Federal Republic of Central America was allowed to re-establish its independence, which it had declared on 1 July 1823.