1Caption: CSS Virginia also known as the Merrimack was an ironclad warship of the Confederate States Navy during the American Civil War (built using the remains of the scuttled USS Merrimack ). Participant in the Battle of Hampton Roads in March 1862 opposite the USS Monitor - the first battle between two powered ironclad warships 2 The Civil War was not only fought on land. There were also some battles at sea. Early in the war, the Union used its ships to block ports in the South. This is called a blockade. At first, small Southern ships could sneak through the blockade and bring goods back to the South. As the war went on, the Union blockade became more effective. Trade to the South was almost completely stopped.3 The South needed a way to break the blockade. One thing that they tried was the ironclad ship. The U.S.S. Merrimack had been a Union ship. It was in Virginia when that state seceded. To keep the Confederates from using it, the ship was burned.4 The Confederates salvaged the ship and rebuilt it. Instead of using only wood, the sides of the ship were covered with iron plates. The Confederates renamed it the Virginia. Today, most historians refer to it by its earlier name.