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
Territorial evolution of North America since 1763 the imperial powers of Europe had the resources to support and expand settlements in North America. As time went on the colonies became more powerful and sought independence from the Old World. These demands for more autonomy sparked several wars, including the American Revolutionary War (1775–1783) and the Mexican War of Independence (1810–1821). The last major colonial power on the continent, the United Kingdom, granted dominion status to Canada in 1867 and slowly turned over its remaining land to that country over the next 100 years, with the last land transfer being the Dominion of Newfoundland in 1949. Throughout this