California was a free state and had been since statehood, more
There was quite a lot of secessionist sentiment in Southern California as the Civil War started, to the point where there was serious discussion of seceding and forming their own CSA-aligned state. What would the effect on the Civil War have been if this had happened?
California was a free state and had been since statehood, more than a decade earlier. No free states seceded; not even all the slave states seceded.
In the 1860 election, only 28 percent of the electorate went for Breckinridge (which in itself was not a marker for disloyalty; many Southern Democrat voters remained loyal, including Breckinridge's running mate), which means at least 72 percent of the electorate voted in favor of overtly anti-secession candidates. A Republican was elected governor early in 1862, succeeding a War Democrat.
During the course of the war, some 17,000 Californians are estimated to have enlisted for the duration with the US forces; another 3,000 served in the state's organized militia during the conflict, for a total of 20,000 from an 1860 census population of ~380,000. Sources are
Dyer, the
Official Records, and the California Adjutant General.
At the same time, a grand total of 21 Californians are known to have made the effort to head east to offer their services to the rebellion. 20,000 to 21 is roughly 900 and some change to 1.
So the odds seem rather high.
Best,