April 24, 1861. San Francisco, California. Brigadier General Edwin V. Sumner relieves Brevet Brigadier General Albert S. Johnston and assumes command of the Department of the Pacific.

Johnston had already resigned his Regular Army commission on April 9, 1861 but refused to abandon his command until properly relieved. General Winfield Scott had ordered Johnston’s return to Washington DC once relieved, but Johnston disregards the directive.

Instead, following Sumner’s arrival, Johnston departed California along with the Los Angeles Mounted Rifles in route to Richmond. Of note, The Los Angeles Rifles were a California mounted infantry militia unit and the only militia from a free state to serve the Confederacy.

Johnston will arrive to Richmond in September 1861. President Jefferson Davis, a long-time friend of Johnston, will appoint him to the rank of general CSA and commander of the Western Department. Johnston will eventually die at the Battle of Shiloh on April 6, 1862.

I must admit, I knew next to nothing about the Secessionist sentiment in parts of California at the outbreak of the war. Found some very interesting reading today, including this one: https://www.kcet.org/shows/lost-la/we-have-been-and-are-yet-secessionist-los-angeles-when-the-civil-war-began