USS Ashuelot was an iron-hulled, double-ended, side-wheel Mohongo-class gunboat in the United States Navy. She was named for a river in New Hampshire. The contract for the construction of Ashuelot was awarded in June or July 1863 to Donald McKay. Her keel was laid down at his shipyard in East Boston, Massachusetts, sometime in 1864; and the ship was launched on 22 July 1865. She was delivered to the Boston Navy Yard on 30 November of that year; but, since the American Civil War had recently ended, the Navy's need for her services had diminished. As a result, Ashuelot — which had been designed for operations in the shallow rivers and coastal waters of the Confederacy — was not placed in commission until 4 April 1866, Commander John C. Febiger in command.