"In the several hundred years of European presence in the New World, Mexico only ruled California for 9 years."
I get 25 years: 1821 to 1846.
1821 = Mexican Independence from Spain (including California)
1846 = Declaration of Independent California Republic (June 10, 1846)
The Reagan administration thought we would have another war with mexico over immigration. Its starting to lok more likely. Thankfully, we are far superior militarily to any spanish speaking country. The only problem I could see is china or russia supporting these people in hopes of weakening the US influence in the world. Thats when the nukes will start flying.
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