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.
History of North America
Meanwhile, Spain's hold on Mexico was weakening. Independence was declared in 1810 by Miguel Hidalgo, starting the "Mexican War of Independence". In 1813, José María Morelos and the Congress of Anáhuac signed the Solemn Act of the Declaration of Independence of Northern America, the first legal document where the separation of the New Spain with respect to Spain is proclaimed. Spain finally recognized Mexico's independence in 1821.