USS Chillicothe, an iron-clad side-wheel steamer, was built at Cincinnati, Ohio, and commissioned 5 September 1862 at Jeffersonville, Indiana, Acting Lieutenant J. P. Sanford in command. Necessary alterations and repairs and lack of sufficient water to pass over the falls detained her in the Ohio River until early January 1863.
From 8 January 1863, when she sailed from Cairo, Illinois until the end of the war, Chillicothe was constantly employed in the Mississippi River and its tributaries. She joined in the expeditions to the White River in Arkansas in January 1863 and to Yazoo Pass, Mississippi, from 20 February to 10 April. Coming under enemy's fire with Baron De Kalb in the Yazoo expedition, Chillicothe was heavily damaged and lost several men. She was sent to Mound City, Illinois for repairs and returned to duty on the Mississippi River 6 September 1863.
On 24 February 1864 she entered the Red River for the expedition of 7 March to 15 May in which her commanding officer, Lieutenant J. P. Couthouy, was mortally wounded by rifle fire 3 April. From 22 May 1864 until 26 May 1865 she lay off Fort Adams, Mississippi on 8 June 1864 assisting in the capture of a Confederate battery at Simmesport, Louisiana.
Chillicothe arrived at Cairo on 13 July 1865, and on 29 November 1865 was sold at auction at Mound City.
Part of the text is incorporated from the United States Navy's Dictionary of American Naval Fighting Ships, a work in the public domain.