Mexican Cession Mexican Cession, with considerable local autonomy punctuated by several revolts and few troops sent from central Mexico, in the period from 1821–22 after independence from Spain up through 1846 when U.S. military forces seized control of California and New Mexico on the outbreak of the Mexican–American War. The northern boundary of the 42nd parallel north was set by the Adams–Onís Treaty signed by the United States and Spain in 1821 and ratified by Mexico in 1831. The eastern boundary of the Mexican Cession was the Texas claim at the Rio Grande and extending north from the headwaters of the Jojo
Historiography of Colonial Spanish America disdain. An important example is Mexico's conservative politician and intellectual Lucas Alamán. His five-volume "Historia de Mejico" is the country's first history, covering the colonial era up to and including the struggle for independence. Alamán viewed crown rule during the colonial era as ideal, and political independence that after the brief monarchy of Agustín de Iturbide, the Mexican republic was characterized by liberal demagoguery and factionalism. Writing in the mid-nineteenth century, Mexican liberal Vicente Riva Palacio, grandson of insurgent hero Vicente Guerrero, wrote a five-volume history of the colonial era from a liberal viewpoint, During the era of Porfirio Díaz