Civil War ramming worked only in restricted circumstances

The American Civil War offered spectacular collisions but weak evidence for making the ram a ship's principal weapon. CSS Virginia nearly endangered herself while ramming Cumberland, and Union monitors defeated other Confederate ironclads with heavy smoothbore gunfire. Restricted river conditions could produce different results, as at Memphis, because ships had less room to evade and tactics were still immature. Even there, success depended on the local engagement rather than a universal superiority of the ram. The broader lesson was to combine armor, heavy guns, maneuverability, and sound construction instead of optimizing a ship around one rare opportunity to collide.