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
Mexican War of Independence The attack was against Gelves as a bad representative of the crown and not against the monarchy or colonial rule itself. There was also a brief conspiracy in the mid-seventeenth century to unite creole elites, blacks, and indigenous against the Spanish crown and proclaim Mexican independence. The man pushing this notion called himself Don Guillén Lampart y Guzmán, an Irishman born William Lamport. Lamport's conspiracy was discovered, and he was arrested by the Inquisition in 1642, and executed fifteen years later for sedition. There is a statue of Lamport in the mausoleum at the base of the Angel of Independence