There was much fighting between ships in the war, but the Union had a stronger and bigger navy. Lincoln put the Confederates under a blockade and so the Union Navy would not let any ships into or out of southern ports. The Confederates used ships called "blockade runners" to bring things from Europe like weapons. The navies of each side also fought on the rivers. The ships included ironclads, which were protected by iron on their sides, and cottonclads, which used cotton along their sides. During the Battle of Hampton Roads, the Confederate ironclad "Virginia" fought against the Union ironclad "Monitor". It was the first time in world history that two ironclads fought each other.