[Footnote 1: Bullock's _Secret Service of the Confederate States in Europe_, Vol. II., pp. 131-163.] %460. The Ironclads.%--To blockade the coast and cut off trade was most important, but not all that was needed. Here and there were seaports which must be captured and forts which must be destroyed, bays and sounds, and great rivers coming down from the interior, which it was very desirable to secure control of. The Confederates were fully aware of this, and as soon as they could, placed on the waters of their rivers and harbors vessels new to naval warfare, called ironclad rams. These were steamboats cut down and made suitable for naval purposes, and then covered over with iron rails or thick iron plates. The most famous of them was the _Merrimac_. [Illustration: %Remodeling the Merrimac%] [Illustration: %The U.S. steamer Merrimac%] %461. The Merrimac or Virginia.%--When Sumter was fired on and the war began, the United States held the great navy yard and naval depot at Portsmouth, Va., where were eleven war vessels of various sorts, and immense quantities of guns and stores and ammunition. But the officer in charge, knowing that Virginia was about to secede, and fearing that the yard would be seized by the Confederates, sank most of the ships, set fire to the buildings, and abandoned the place. The Confederates at once took possession, raised the vessels, and out of one of them, a steamer called the _Merrimac_. made an ironclad ram, which they renamed the _Virginia_ and sent forth to destroy the wooden vessels of the United States then assembled in Chesapeake Bay. Well knowing that he could not be harmed by any of our war ships, the commander of the _Merrimac_ went leisurely to work and began (March 8, 1862) by attacking the _Cumberland_. In her day the _Cumberland_ had been as fine a frigate as ever went to sea; but the days of wooden ships were gone, and she was powerless. Her shot glanced from the sides of the _Merrimac _like so many peas, while the new monster, coming on under steam, rammed her in the side and made a great hole through which the water poured. Even then the commander of the _Cumberland_ would not surrender, but fought his ship till she filled and sank with her guns booming and her flag flying. After sinking the _Cumberland_, the _Merrimac_ attacked the _Congress_, forced her to surrender, set her on fire, and, as darkness was then coming on, went back to the shelter of the Confederate batteries. [Illustration: Monitor, side and deck plan]