A plausible Emperor Norton?

[Keenir]

We all know of Emperor Norton, a rice seller who made proclamations without backing (ie the disolving of the US by force)

but was there anyone in the 1800s - in northwest Mexico, California, New Mexico, Oregon, Arizona - who could have led an independent nation? (ie "the Sister Republic" some US politicians said they would welcome California as)

are the Mormons our only prospect? or the Chinese immigrants? (that would be interesting)

 

[Rogue Shadows]

We all know of Emperor Norton, a rice seller who made proclamations without backing (ie the disolving of the US by force)

but was there anyone in the 1800s - in northwest Mexico, California, New Mexico, Oregon, Arizona - who could have led an independent nation? (ie "the Sister Republic" some US politicians said they would welcome California as)

are the Mormons our only prospect? or the Chinese immigrants? (that would be interesting)

The Mask of Zorro

Have someone like Diego de la Vega make a similar plan as Vega's work: California is bought from Mexico by people hoping to found a sovereign nation on their own terms, using Californian gold discovered early (and before the rest of Mexico learns of it).

Unlikely? Yes - but it's not the least likely thing to happen in history. Perhaps the region could consist of California, Nevada, and Baja California.

Following the Mexican-American War, have California "discover" its huge gold reserves, and you get an influx of immigrants from the US that allow you to start building a proper nation.

BONUS ROUND!
Have the Republic of California be rife with internal discontent. A man by the name of Joshua Norton enters...

 

[The Vulture]

Best bet is probably a mercenary like William Walker or Lee Christmas. They'll probably have some sort of corporate backing, and it'd probably be more in Northern Mexico. Perhaps to secure rail passage through Mexico or a buffer state.

 

[zoomar]

Actually, not being a Californian, I had to look him up.
Do you mean before or after these areas became part of the US? Either way, about the only way such an independent state could last is if its existence was viewed by the USA as a way to protect or extend US geopolitical or economic interests without actually extending full US citizenship to its inhabitants. If things had gone differently, the Mormons in Utah could have been such an example. Indian Territory perhaps. Maybe railroad barons allowed to carve out a "nation" to contain the transcontinental RR? While not actually in the area of discussion, the best example might be Hawai'i. The US could have decided not to annex the Islands after the monarchy was overthrown, but instead to recognize and prop up the new "Republic" in exchange for military and economic concessions.