When the state of Virginia seceded from the Union in 1861, one of the important Federal military bases threatened was Norfolk Naval Yard. Accordingly, the order was sent to destroy the base rather than allow it to fall into Confederate hands. Unfortunately for the Union, these orders were bungled. The steam frigate, USS Merrimac, sank before she completely burned. When the Confederates entered the yard, they raised the Merrimac and decided to use her engines and hull to build an ironclad warship.
This new ship was named the CSS Virginia. She had an iron deck and casement, four inches thick. She mounted ten cannon, one in front and rear and four on each side. The Merrimac's engines, now part of the Virginia, were not in good working order and had not been improved by being submerged in the James River. The addition of a number of tons of iron did not help the situation.
On 8 March 1862, the Virginia set out for Hampton Roads, where part of the Union blockading fleet was anchored. The wooden ships of the fleet proved no match for the ironclad and the USS Congress and USS Cumberland were destroyed. The USS Minnesota ran aground trying to avoid the Virginia. It being late in the day, the Virginia left with the expectation of returning the next day and completing the destruction of the Union fleet.
Later that night, the USS Monitor arrived. This Union ironclad had been rushed to Hampton Roads in hope of protecting the Union fleet and preventing the Virginia from threatening Union cities.
The next day, 9 March 1862, the world's first battle between ironclad warships took place. The smaller and nimbler Monitor was able to outmaneuver the Virginia but neither ship proved able to greatly damage the other. Finally, the Virginia retreated back up the James river, leaving the Monitor and the rest of the Union fleet in possession of the battlefield.
During the next two months, the Virginia made several sorties to Hampton Roads hoping to draw the Monitor into battle. The Monitor, however, was under orders not to engage the Virginia and refused to fight her.
Finally on 10 May 1862, advancing Union troops threatened to capture Norfolk. The Virginia was unable to retreat further up the James river due to her deep draft. So she was ordered burnt to keep her from being captured. Early on the morning of 11 May 1862, the flames reached her magazine and the ship was destroyed by a great explosion.