1862 Battle of Hampton Roads
One of the North’s most effective tactics in the battle against the Confederacy was a naval blockade of southern ports. This hampered the import of arms and vital supplies and cut off the export of cotton to Europe, a major source of income. In order to thwart this embargo, the Confederate navy took the hull and engines of a captured US frigate USS Merrimack, armour plated it and mounted 14 guns and a ram, turning it into the ironclad CSS Virginia.
On March 8, 1862 the Virginia fought a successful engagement against the Union navy, sinking wooden vessels, USS Congress and USS Cumberland, and forcing a third, USS Minnesota to run aground. Virginia was mauled during the fray but returned the following day to complete her mission. In this she found herself confronted by a rival ironclad, USS Monitor, a vessel quite unlike the Virginia in build and armament which had hurried south from Brooklyn to confront its rival.
Monitor was lower and nimbler, though outgunned. She pounded Virginia with her two smoothbore guns in a revolving turret and Virginia thundered back but no significant damage was done to either vessel in this, the first battle between ironclads. Both ships retired from the action and never fought each other again. Virginia would be scuttled a few months later and Monitor would sink in a storm by the end of 1862.