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.
American frontier
Mexico became independent of Spain in 1821, and took over Spain's northern possessions stretching from Texas to California. Caravans began delivering goods to Mexico's Santa Fe along the Santa Fe Trail, over the journey which took 48 days from Kansas City, Missouri (then known as Westport). Santa Fe was also the trailhead for the "El Camino Real" (the King's Highway), a trade route which carried American manufactured goods southward deep into Mexico and returned silver, furs, and mules northward (not to be confused with another "Camino Real" which connected the missions in California). A branch also ran eastward near the Gulf (also called the Old San Antonio Road). Santa Fe connected to California via the Old Spanish Trail.