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 Dis