USS Agamenticus (1863)

USS Agamenticus was a Miantonomoh-class monitor of the United States Navy, named after Mount Agamenticus in York County, Maine.

The twin-screw, double-turreted ironclad monitor was laid down sometime in 1862 at Portsmouth Navy Yard in Kittery, Maine and launched on 19 March 1863. Since operational experience with the monitors during the American Civil War had shown the necessity for better ship-control and navigational facilities, Agamenticus underwent alterations in the first few months of 1864, notably the addition of a "hurricane deck" that extended between the two turrets and over the machinery spaces amidships.

Service history
Commissioned on 5 May 1864 at Portsmouth, Lieutenant Commander C. H. Cushman in command, Agamenticus operated off the northeast coast of the United States, from Maine to Massachusetts, until decommissioned at the Boston Navy Yard on 30 September 1865. She remained laid-up for nearly five years and, during that time, on 15 June 1869, was renamed Terror.

She reentered commissioned service in late May 1870. The monitor operated in the western Atlantic and in the Gulf of Mexico until June 1872, when she was again laid up, this time at the Philadelphia Navy Yard, Pennsylvania. Two years later, she was broken up and her name used in building a new monitor, which was finally commissioned more than two decades later as USS Terror.