The District of California was a Union Army command department formed during the American Civil War. The district was part of the Department of the Pacific, the commander of the department also being District commander. The district was created as a separate command on July 1, 1864, after Irvin McDowell took command of the Department of the Pacific, relieving General Wright, who then remained as District of California commander. The District comprised the state of California and the areas of the Rogue River and Umpqua River in Southern Oregon. Its headquarters were in San Francisco, co-located with those of the Department of the Pacific. On March 14, 1865, the District of Oregon was extended to include the entire state of Oregon, removing the Rogue River and Umpqua River areas from the District.
January 15, 1861. The Departments of California and Oregon merged into the Department of the Pacific. Col. Albert Sidney Johnston, 2nd US Cavalry, Brevet Brigadier General, U. S. Army, assumes command of the Department of the Pacific.
March 23, 1861. Brigadier General Edwin V. Sumner, U. S. Army, assigned to command the Department of the Pacific.
April 25, 1861. Brig. Gen. Edwin V. Sumner, U. S. Army, assumes command of tho Department of the Pacific, relieving Col. Albert Sidney Johnston, 2nd US Cavalry, brevet brigadier-general, U. S. Army.
Sept. 25, 1861. The District of Southern California created, comprising the counties of San Luis Obispo, Tulare, Santa Barbara, Los Angeles, San Bernardino, and San Diego, and Col. George Wright, assigned to its command.
Oct. 11, 1861. Lieut. Col. Albemarle Cady, 7th US Infantry, assigned to command the District of Oregon.
Oct. 20,1861. Brig. Gen. Edwin V. Sumner, U. S. Army, relinquishes command of the Department of the Pacific to Col. George Wright.
Oct. 26,1861. Col. George Wright, assumes command of tho Department of the Pacific.
Nov. 19,1861. Brig. Gen. George Wright, U. S. Army, formally assigned to command the Department of the Pacific.
Dec. 12, 1861. Humboldt Military District created to prosecute the Bald Hills War, to consist of the counties of Sonoma, Napa, Mendocino, Trinity, Humboldt, Klamath, and Del Norte, in Northern California, and Col. Francis J. Lippitt, Second California Infantry, assigned to its command.
1862
Sept. 21,1862. Affair on the Yreka Road, near Fort Crook, Cal.
Nov. 3-29, 1862. Scouts from Fort Crook, Cal., and Fort Churchill, Nev. Ter., to Honey Lake Valley, Cal.
1863 1864
July 1, 1864. Brig. Gen. George Wright, U. S. Army, retained command of the District of California but Maj. Gen. Irvin McDowell, U. S. Army, relieved him and assumed command of the Department of tho Pacific.
1865
Apr. 5-18,1865. Expedition from Camp Bidwell to Antelope Creek, Cal.
June 27, 1865. Military Division of the Pacific created, to consist of the Departments of California and the Columbia. Department of California consisted of the States of California and Nevada and the Territories of New Mexico and Arizona. Maj. Gen. Irvin McDowell, U. S. Army, assigned to command the Department of California.