1836 - Mexico City begins to secularize missions and begins to establish rule of civil law through the presence of Mexican troops and on-site governors. Secularization completed by 1839.
1842- Last Mexican governor dispatched to California. Home rule revolt, not involving non-Hispanic, white Europeans, or illegal, US immigrants, starts upon arrival and governor forced to flee in 1845. At that time California had about 100K natives, 9K Mexicans and 2K illegal immigrants from the US.
1845 - US begins to explore Alta California with both troops and warships.
1846 - Bear Flag revolt and war between Mexico and US.
1847 - Cahuenga Capitulation in January 1847
Campo Cahuenga is right down the road!