High Quality Content by WIKIPEDIA articles! The contract for construction of USS Manayunk was signed by agents of the United States Navy and the shipbuilding firm of Snowden and Mason on 15 September 1862, and the keel of the Canonicus-class monitor was laid down shortly thereafter at Pittsburgh, PA The ship was ready to be launched in April 1864, but her entry into water was delayed by the very low level of the Ohio River. She finally slid down the ways on 18 December; but, by that time, most of the naval phase of the American Civil War had ended. Therefore, the ship`s fitting out was halted before she received her two 15 in (380 mm) Dahlgren smoothbore guns. She was towed to the naval station at Mound City, IL, and laid up until 1867, when she was towed down the Mississippi River and again laid up, this time at New Orleans, LA. While there, Manayunk was renamed Ajax on 15 June 1869.