CSS ALBEMARLE  'Ironclad in a Cornfield'
By late evening of April 19, 1864, one Union gunboat could be seen fleeing to the east away from its post guarding the river flank of Union forces in Plymouth, North Carolina. Another gunboat, the Southfield, lay on the bottom of Albemarle Sound with a very large hole in her side put there in a ramming action by a dangerous adversary. Her name was CSS Albemarle - and she had indeed been built in a cornfield on a riverbank far up the Roanoke River by Confederate naval officers and a resourceful contingent of southern farmers and carpenters. Sadly underestimated by the Union commanders, the Albemarle had completed her part in the mission of a combined land and naval force to recapture Plymouth.

CSS ARKANSAS
On July 15, 1862, one of the most stirring exploits in American naval history occurred. The CSS Arkansas, a homebuilt Confederate ironclad covered in railroad iron, descended the Yazoo River in Mississippi and steamed alone with guns blazing through two combined Union naval forces which barred the Ironclad's course. The mission of the Arkansas on that day was to reach Vicksburg located on the Mississippi River and help defend the city from an immense Union force. The ensuing battle caused considerable confusion, damage and great embarrassment to the Union fleet as it was taken by surprise by the rusty-brown Arkansas. The heavily outnumbered rebel ship had even disabled and run aground the Ironclad gunboat Carondelet in the initial phase of the conflict. Her mission was accomplished although she did not escape damage free.

THE CAIRO CLASS OF GUNBOATS   Built by James B. Eads..
A total of seven gunboats represented this class of western river Ironclads:
St Louis (later renamed Baron de Kalb); Cairo; Carondelet; Cincinnati; Mound City; Louisville; Pittsburgh.

Although only partially armoured, they represented the first ironclad vessels built by the Union and were the early work horses on western waters primarily throughout 1862 and 1863. Some went into action capturing Fort Henry on the Tennessee River even before the Monitor met the Merrimac in Hampton Roads.

USS PASSAIC
Built in various ship yards for the US Navy during the Civil War, a total of ten ships represented this class of improved  monitors: Passaic, Camanche, Catskill, Conestoga, Lehigh, Montauk, Nahant, Nantucket, Patapsco and Weehawken.

As the Passaic class was an improved design over the original USS Monitor, the Canonicus class carried these improvements further. They were stronger along the waterline from increased armor. Pilot house armor was also increased.