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
Rancho Santiago de Santa Ana County given under Spanish Rule which were rare during this time. This was only two and a half months before the start of the war for Mexican Independence (1810-1821). The surrounding land grants or ranchos were granted by the Mexican government after Mexican independence in 1821. José Antonio Yorba built an elaborate adobe hacienda, El Refugio (the Refuge), located near present-day First and Sullivan Streets in western Santa Ana. With the Mexican Cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored. As required by