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.
Spanish Empire
A long period of wars followed in America from 1811 to 1829. In South America this period of wars led to the independence of Argentina (1810), Venezuela (1810), Chile (1810), Paraguay (1811) and Uruguay (1815, but subsequently ruled by Brazil until 1828). José de San Martín campaigned for independence in Chile (1818) and in Peru (1821). Further north, Simón Bolívar led forces that won independence between 1811 and 1826 for the area that became Venezuela, Colombia, Ecuador, Perú and Bolivia (then Alto Perú). In the Viceroyalty of New Spain, free-thinking secular priest, Miguel Hidalgo y Costilla, declared Mexican freedom in 1810 in the Grito de Dolores. Independence was actually won in 1821 by a royalist army officer turned insurgent, Agustín de Iturbide, in alliance with insurgent Vicente Guerrero and under the Plan of Iguala. The conservative Catholic hierarchy in New Spain supported Mexican independence largely because it found the liberal Spanish Constitution of 1812 abhorrent.