Confederate States of America, ironclad, 1862 The CSS Virginia was built by the Confederates (South) during the American Civil War to try and break the blockade the Union (North) had placed on the Southern ports. Based on the hull and machinery of the USS Merrimack, a modern steam frigate, she was built with a iron upperworks or casemate continaining her armament. The Virginia met the Union Ironclad USS Monitor at the battle of Hampton Roads on 9th March 1862. Neither ship was badly damaged in the encounter, but the failure to break the blockade ultimately meant the defeat of the South.