Department of California

The Department of California was one of two Army Departments created September 13, 1858, replacing the original Department of the Pacific and was composed of the territory of the United States lying west of the Rocky Mountains and south of Oregon and Washington territories, except the Rogue River and Umpqua Districts of southwestern Oregon Territory, which were assigned to the Department of California and excluding the Utah Territory east of the 117th meridian west and New Mexico Territory east of the 110th meridian west. Its creation was authorized by General Orders, No. 10, of the War Department, Adjutant-General's Office, September 13, 1858. Headquarters as before remained at San Francisco.

The Department of California was commanded first by Brevet Brigadier General Newman S. Clarke, Colonel U.S. 6th Infantry Regiment, until his death on October 17, 1860. It was next commanded by Lt. Colonel Benjamin L. Beall, U.S. 1st Dragoon Regiment, who had assumed command, by seniority of rank, on the death of General Clarke, on October 17, 1860. It was merged into the restored Department of the Pacific on January 15, 1861, as the District of California administering the same territories, under Brevet Brigadier General Albert Sidney Johnston from January 15, 1861.

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