The goal of this article is to highlight the military, social, and political issues between Northern and Southern sympathizers in California during the American Civil War. The California Gold Rush saw many Americans move west to cash in on the Gold Mines of the Sierra Nevada Mountains. However, the move west also meant that people would bring their politics and ideas with them, which included how to create slave and free territory. California would become a free state due to the Missouri Compromise, but many Southerners living in the state contested the idea. During California's first decade of statehood, state politicians with Southern backgrounds fought to make California a slave state.

California's Southern sympathies during the Civil War turned the state into a border state. Newspapers and politicians with deep Southern ties denounced the Union Government. California would not see a Pro-Union state government elected until 1862. Even though the statehouse was for the Union, Pro-Southerners continued to weaken the state for the Confederacy. One of the concerns for politicians not securing California for the Union was Confederate expansion. The worry of many in Washington DC was a Confederate expansion to the Pacific Ocean. Pro-Southern ties in California would allow the Confederate Army would have easy access to California due to the small military presence in the West. In order to combat this, the Union Army and the California state government had to identify the state's Pro-Southern elements. Removing Southern sympathies in California would take until the end of the Civil War.