Spanish attempts to reconquer Mexico
Mexican independence was officially achieved on September 27, 1821, under the Treaty of Córdoba. Spain did not recognize the treaties, arguing that the viceroy Juan O'Donojú had no authority to recognize the independence of any overseas province. This situation was dangerous to the newly acquired independent status of the nation, which had not yet been recognized by any of the European powers that could support it, and the threat of Spanish reconquest was a constant worry to the leaders of the nascent regime. On May 13, 1822 decrees were issued by the government to imprison anyone who conspired against Mexico's independence.
Postage stamps and postal history of Mexico
Mexico declared independence from Spain on September 16, 1810. This resulted in the long Mexican War of Independence which ended in 1821, and which eventually led to the creation of the short-lived First Mexican Empire. Agustín de Iturbide was the first and only emperor. Two years later, he was deposed by the republican forces. In 1824, a republican constitution was adopted, creating the United Mexican States with Guadalupe Victoria as its first President.