He arrived, though not as soon as anticipated, was most opportune and important. For some time the Department had heard with great solicitude of the progress which the insurgents had made in armoring and equipping the large war-steamer Merrimac, which had fallen into their hands when Norfolk was abandoned. On the afternoon of the 8th of March this formidable vessel, heavily armored and armed and fully prepared to operate both as a ran and a war steamer, came down the Elizabeth River, accompanied by several small steamers, two of them partially armored, to attack the vessels of the blockading squadron that were in and about Hampton Roads. When the Merrimac and her attendants made their appeared off Newport News, and the remaining vessels were in the vicinity of Fortress Monroe, some 6 miles distant. The Minnesota, the Roanoke, and the St. Lawrence got immediately under way and proceeded toward the scene of action.

The Congress, being nearest to the Merrimac, was the first to receive her fire, which was promptly returned by a full broadside, the shots falling apparently harmlessly off from the armored side of the assailant. Passing by the Congress, the Merrimac dashed upon the Cumberland, and was received by her with a heavy, well-directed, and vigorous fire, which, like that of the Congress, produced unfortunately but little effect. A contest so unequal could not be of long continuance, and it was closed when the Merrimac, availing of her power as a steam ram, ran furiously against the Cumberland, laying open her wooden hull, and causing her almost immediately to sink. As her guns approached the water's edge he young commander, Lieutenant Morris, and the gallant crew stood firm at their posts, delivered a parting fire, and the good ship went down heroically, with her colors flying. Having thus destroyed the Cumberland, the Merrimac turned again upon the Congress, which had, in the mean time, been engaged with the smaller rebel steamers, and after a heavy loss, in order to guard against such a fate as that which had befallen the Cumberland, had been run aground. The Merrimac now selected a raking position astern of the Congress, while one of the smaller steamers poured in a constant fire on her starboard quarter. Two other steamers of the enemy also approached from James River, firing upon the unfortunate frigate with precision and severe effect. The guns of the Congress were almost entirely disabled, and her gallant commanding officer, Lieutenant Joseph B. Smith, had fallen at his post. Her decks were strewn with the dead and dying, the ship was on fire in several places, and not a gun could be brought to bear upon the assailants. In this state of things, and with no effectual relief at hand, the senior surviving officer, Lieutenant Pendergrast, felt it his duty to save further useless destruction of life by hauling down his colors. This was done about 4 o'clock p. m. The Congress continued to burn till about 8 in the evening and then blow up.

From the Congress the Merrimac turned the attention to the remaining vessels of the squadron. The Roanoke had grounded on her way to the scene of the conflict; and although she succeeded in getting off, her condition was such, her propelled being useless, that she took no part in the action. The St. Lawrence also grounded near the Minnesota and had a short engagement with the Merrimac, but suffered no serious injury, and on getting afloat was ordered back to Fortress Monroe.

The Minnesota, which had also got aground in the shallow waters of the channel, become the special object of attack, and the Merrimac,