the turret to protect the crew against Confederate snipers based on a suggestion by Commander Tunis A. M. Craven, captain of her sister ship . Construction The contract for Canonicus, the first Navy ship to be named for the chief of the Narragansett Indians, was awarded to Harrison Loring; the ship was laid down in 1862, at their Boston, Massachusetts, shipyard. She was launched on 1 August 1863, and commissioned on 16 April 1864, with Commander E. G. Parrott, in command. The ship's construction was delayed by multiple changes ordered while she was being built that reflected battle experience with earlier monitors. This included the rebuilding of the turrets and pilot houses to increase their armor thickness from to 10 inches, and to replace the bolts that secured their armor plates together with rivets, to prevent them from being knocked loose by the shock of impact from shells striking the turret. Other changes included deepening the hull by to increase the ship's buoyancy, moving the position of the turret to balance the ship's trim, and replacing all of the ship's deck armor. As far as is known the ship was not modified after her completion. Service history Canonicus sailed from Boston, on 22 April 1864, and arrived at Newport News, Virginia, on 3 May, for service with the James River Flotilla. She reached the mouth of the Appomattox River, by 5 May. By 22 May, the ship was deployed with her sisters and Tecumseh on the James River, where they protected the transports of Major General Benjamin Butler's Army of the James, supplying the army as it operated on the south bank of the river during the Bermuda Hundred Campaign. On 21 June, Commander Craven, of Tecumseh, spotted a line of breastworks that the Confederates were building at Howlett's Farm, and his ship opened fire at the workers. The Confederates replied with a battery of four guns near the breastworks and Saugus and Canonicus joined in the bombardment. A half-hour later, Confederate ships near Dutch Gap joined in, but their fire was ineffective because they were firing blindly at the Union monitors. During the engagement Canonicus fired forty 15-inch shells and was hit twice by Confederate shells. One shell pierced the upper part of the funnel and the other struck the deck and ricocheted into the turret; no one was wounded or killed during the engagement. The ship dueled with