California was one of the most. The capital of Alta California remained Monterrey, as it had been since the Portolá expedition of 1769 first established an Alta California government, and local political structures did not change. The Portolá overland expedition arrived at the site of present-day San Diego on June 29, 1769, where it established the Presidio of San Diego and annexed the adjacent village of Kumeyaay of Kosa'aay, making San Diego the first European settlement in present-day California. By the end of the 19th century, California remained largely rural and agricultural, with a population of about 1.4 million inhabitants.
Vallejo consulted with Castro and Alvarado recommending that Mexico send military reinforcements to enforce its military control of California. During the last quarter of the 18th century, the first Spanish settlements were established in what later became the Province of Las Californias of the Viceroyalty of New Spain. Some estimates can be obtained from Alta California newspapers published in san francisco in 1850. In May 1847, after the end of the war between Mexico and the United States, Richard Mason was appointed military governor of California.
Faced with such rapid growth, as well as a thorny debate in Congress on the question of slavery in the new territories, Congress allowed California to jump straight to full statehood without ever going through the formal territorial stage. The contraband could have been sent across the Gulf of California to enter the mainland of Mexico through Sonora, where the Jesuits also had missions and sympathies for their funders. Before Europeans landed in North America, about one-third of all natives of what is now the United States lived in the area that is now California. The victory in the Mexican War of Independence from Spain in 1821 marked the beginning of Mexican rule in California, in theory, although in practice the First Mexican Empire did so during its reign.
Alvarado notified Vallejo of the situation, and in April the California military began arresting U.S. and English immigrants, and finally detained about 100 in the Presidio de Monterrey. With U.S. forces combined with a total of 660 troops, they fought the Californians in the Battle of Rio San Gabriel.
As the successor state of the viceroyalty of New Spain, Mexico automatically included the provinces of Alta California and Baja California as territories. Senior members of the Alta California legislature, Juan Bautista Alvarado and José Castro, with the support of Mariano Guadalupe Vallejo, Commander of the Fourth Military District and Director of Colonization of the Northern Border, and the assistance of a group of Americans led by Isaac Graham, staged a revolt in November 1836 and forced to Gutiérrez to resign from power. Frémont, with about 60 well-armed men, had entered California in December 1845 and was making a slow march towards Oregon when they learned that the war between Mexico and the U.