There was a vocal secessionist faction in Southern California.

Northern California was safely held by the Union during the secession crisis. Southern California had significant Confederate sympathies despite being a free Union state.

A vociferous minority of Southerners who had migrated to Southern California during the Gold Rush aspired for the region to split from the Union and join the Confederacy. The Los Angeles Mounted Rifles and local chapters of the Knights of the Golden Circle, a group that had previously been committed to annexing 25 states in Mexico to be added to the United States as slave states, were among the pro-Confederate organizations that rose as a result of this vocal movement. Due to the significant number of Southerners who had relocated to the Southern California region, these Confederate ties existed. Lincoln only garnered 25% of the Los Angeles vote in the 1860 presidential election, demonstrating this prejudice.