Department of the Ohio

The Department of the Ohio was an administrative military district created by the United States War Department early in the American Civil War to administer the troops in the Northern states near the Ohio River.

General Orders No. 14, issued by the Adjutant General's Office in Washington, D.C., on May 3, 1861, combined all Federal troops in the states of Ohio, Indiana, and Illinois in a new military department called the Department of the Ohio, with headquarters in Cincinnati, Ohio. Maj. Gen. George B. McClellan was designated as its first commander. McClellan led efforts in the spring and early summer of 1861 to occupy the area of western Virginia that wanted to remain in the Union. His forces defeated two small Confederate armies and paved the way for the region to later became the state of West Virginia.

After McClellan was reassigned to command the Army of the Potomac, Brig. Gen. Ormsby M. Mitchel commanded the Department of the Ohio from September to November 1861. Under his directive, troops pushed southward towards Huntsville, Alabama, from Chattanooga, Tennessee, but were turned away. Then, General Orders No. 97 commanded Maj. Gen. Don Carlos Buell to assume command of the department. All the forces of the department were then organized into the Army of the Ohio with Buell in command. The Department of the Ohio was dissolved in March 11, 1862, when it was merged into the Department of the Mississippi and the Department of the Mountains.

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