The "Merrimac" was steering straight for the "Cumberland," in grim silence, her unarmoured consorts keeping well astern. When the range was about three-quarters of a mile the two Federal ships opened fire with the heavy guns mounted on pivots on their upper decks, and the shore batteries also brought some guns to bear. A heavy cannonade from sea and shore was now echoing over the landlocked waters, but the "Merrimac" fired not a gun in reply. A few cannon-shot struck her sloping armoured sides, and rebounded with a ringing clang. The rest ricochetted harmlessly over the water, throwing up sparkling geysers of foam in the bright sunlight.

At last, when the range was only some 500 yards, the bow-gun of the "Merrimac" was fired at the "Cumberland," with an aim so true that it killed or wounded most of the men at one of her big pivot-guns. A moment after the ram was abeam of the "Congress," and fired her starboard battery of four guns into her at deadly close range. With the projectiles from 25 guns of the "Congress" and 15 of the "Cumberland" rattling on her armour, riddling her funnel, and destroying davits, rails, and deck-fittings, the "Merrimac" steamed straight for the "Cumberland," which made an ineffectual attempt to avoid the coming collision. At the last moment some men were killed and wounded in the gun-deck of the ram by shots entering a port-hole. Then came a grinding crash as the iron ram of the "Merrimac" struck the "Cumberland" almost at right angles on the starboard side under her fore-rigging. On board the Confederate ship the shock was hardly felt. But the "Cumberland" heeled over with the blow, and righted herself again as the "Merrimac" reversed her engines and cleared her, leaving a huge breach in the side of her enemy. The ram had crushed in several of her frames and made a hole in her side "big enough to drive a coach and horses through." The water was pouring into her like a mill-race.

From the "Merrimac," lying close alongside with silent guns, came a hail and a summons to surrender. From the deck of the "Cumberland" her commander, Morris, replied with a curt refusal. The firing began again; the "Cumberland's" men, driven from the gun-deck by the inrush of rising water, took refuge on the upper deck. Some jumped overboard and began swimming ashore. Others kept her two pivot-guns in action for a few minutes. Then with a lurch she went down. Boats from the shore saved a few of her people. Those who watched from the batteries could hardly believe their eyes as they saw the masts of the warship sticking out of the water where a few minutes ago the "Cumberland" had waited in confidence for the attack of the improvised "rebel" ironclad.

As her adversary went down, the "Merrimac" turned slowly to menace the "Congress" with the same swift destruction. She took no notice of the harmless cannonade from the shore. Lieutenant Smith, who commanded the "Congress," had realized that collision with the enemy meant destruction, rapid and inevitable, and decided that his best chance was to get into shoal water under the batteries. He had slipped his cable, shaken out some of his sails, and signalled to the tug-boat "Zouave" to come to his help. The "Zouave" made fast to the "Congress" on the land side, but she had not moved far when the ship grounded within easy range of the "Merrimac's" guns. These were already in action against her.

The leading ship of the seaward Federal squadron, the frigate "Minnesota," had come in within long range, and opened on the "Merrimac" and the gunboats. But she had only fired a few shots when she also ran aground on the edge of the main channel, but in such a position that some of her guns could still be brought to bear. Taking no notice of this more distant foe, the "Merrimac" devoted all her attention to the "Congress." She sent a broadside into the stranded frigate, and then passing under her stern, raked her fore and aft and set her on fire. Lieutenant Smith, of the "Congress," was badly wounded. Lieutenant Prendergast, who succeeded to the command, decided that with his ship aground and the enemy able quietly to cannonade her without coming under fire of most of her guns, to prolong the fight would be to waste life uselessly. After consulting his wounded chief he dipped his colours and displayed a white flag. The little "Zouave" cast off from the frigate, and as she cleared her, fired a single shot from her one gun at the "Merrimac," and then ran down to the "Minnesota." This shot led afterwards to a false report that the "Congress" had reopened fire treacherously after surrendering.

Civil war has often been described as fratricidal. In this action between the "Congress" and the "Merrimac" two brothers were opposed to each other. Commodore Buchanan, who commanded the "Merrimac," knew, when he attacked the "Congress," that a younger brother of his was a junior officer of the frigate. The younger man escaped unscathed, but the commodore was slightly wounded during the fight. When the "Congress" struck her colours, Buchanan ordered two of the gunboats to take off her crew. Her flag was secured to be sent to Richmond as a trophy. While the gunboats "Raleigh" and "Beaufort" were taking off the Federal wounded, there came from the batteries on shore a heavy fire of guns and rifles. Several of the wounded and two officers of the "Raleigh" were killed, and the gunboats drew off, leaving most of the crew of the "Congress" still on board. They escaped to the shore in boats and by swimming. Meanwhile the "Merrimac" fired a number of red-hot shot into her, and she was soon ablaze fore and aft. Then the ironclad turned and fired at the "Minnesota."

The sun was going down and the tide was running out rapidly. The deep draught of the "Merrimac" made the risk of grounding, if she closely engaged the "Minnesota," a serious matter. So Buchanan signalled to the gunboats to cease fire, and, accompanied by them, steamed over to the south side of the Roads, where he anchored for the night under the Confederate batteries, intending to complete the destruction of the Federal fleet next morning.

The first day's fight was over. It had been a battle between the old and the new—between a steam-propelled armoured ram and wooden sailing-ships. The "Cumberland" had been sunk, the "Congress" forced to surrender and set on fire, and the "Minnesota" was hopelessly aground and marked down as the first victim for next day. The Federals had lost some two hundred men. The Confederates only twenty-one. Buchanan was wounded, not severely, but seriously enough for the command of the "Merrimac" to be transferred to Lieutenant Jones. As night came on the moon rose, but the wide expanse of water was lighted up, not by her beams only, but also by the red glare from the burning "Congress." The flames ran up her tarred rigging like rocket trails, masts and spars were defined in flickers of flame. At last, with a deafening roar that was heard for many a mile, she blew up, strewing the Roads with scattered wreckage.

At ten o'clock that evening, while the "Congress" was still burning, a strange craft had steamed into the Roads from the sea, all unnoticed by the Confederates. She anchored in the shallow water between the "Minnesota" and the shore. Her light draught enabled her to go into waters where less powerful fighting-ships would have grounded. To use the words of one who first saw her as the sun rose next day, she looked like a plank afloat with a can on top of it. She was Ericsson's ironclad turret-ship, the "Monitor."

In the first weeks of the war inventors had besieged the United States Navy Department with proposals for the construction of ironclad warships. The Department was still leisurely debating as to what policy should be adopted, when news came that the "Merrimac," half-burnt at Norfolk Yard, was being reconstructed as an armoured ram, and it became urgent to provide an adversary to meet her on something like equal terms. It was at this moment that John Ericsson came forward with his offer to construct an armoured light-draught turret-ship, which could be very rapidly built and put in commission. This last point was of cardinal importance, for report said that work on the "Merrimac" was far advanced, and no ship could be built on ordinary lines, of sufficient power to meet her, in the time now available. The vessel must be of light draught to work in the shallow coast waters, creeks, and river mouths of the Southern States. She might have to fight in narrow channels, where there would not be room for manœuvring to bring broadside guns to bear. Ericsson, therefore, proposed that her armament should be a pair of heavy guns mounted in a turret, which could be revolved so as to point them in any direction, independently of the position of the ship herself.