Few days opened more darkly for the U.S. Navy than March 9, 1862.
Mangled by the lethal guns and armored sides of the CSS Virginia on the previous afternoon, the Union fleet in Hampton Roads still reeled from the brutal loss of two warships and 300 sailors. And as the morning fog burned off, the USS Minnesota remained stuck in the shoals, making a desperate target for the expected return of the fearsome rebel marauder.
Just how much alarm the bloody defeat had caused can be seen in the dispatches of Maj. Gen. George B. McClellan, who authorized the evacuation of Newport News Point if needed - then ordered the garrison at Fort Monroe to hold "at all hazards" if the Confederate ironclad attacked. In Washington, D.C., Secretary of War Edwin Stanton worried aloud at an emergency Cabinet meeting that the smoke-belching monster might appear to shell the White House "before we leave the room."
Even those who saw the USS Monitor slip into Hampton Roads just hours after the rampage ended had no doubt who would prevail in a clash between the curious little ship and the Confederate behemoth.
"An atmosphere of gloom pervaded the fleet," Executive Officer Lt. Samuel D. Greene reported.
"And the pygmy aspect of the newcomer did not inspire confidence among those who had witnessed the day before."
Still, if the historic start of the Battle of Hampton Roads proved the power of iron over wood, the thundering 4-hour slugfest that took place on the second day changed the course of war at sea for generations.
So advanced was the little Monitor and its revolving gun turret that the startled British admiralty stopped work on all wooden ships immediately, while the Times of London lamented the sudden obsolescence of all but the two ironclad vessels in the huge 149-ship Royal Navy.
"March 8 is the day that ends centuries of naval tradition - but the next day is the one that sealed the deal and defined the future," said Anna Holloway, curator of the USS Monitor Center at The Mariners' Museum.
"Both days, thousands of people watched with disbelief. No one had ever seen anything like it."
As great as the confusion caused by the appearance of the Virginia on March 8, the sight of the Monitor as it steamed out toward its foe was still stranger and more bewildering.
Aboard the rebel ship - which had been radically transformed from the burned-out hull of the old USS Merrimack - the crew looked on with wonder as the low-slung craft and its mystifying iron drum left the shadow of the towering Minnesota.
Just as puzzled was Lt. James H. Rochelle, commander of the rebel escort vessel CSS Patrick Henry.
"(It was) such a craft as the eyes of a seaman never looked on before," he said.
"An immense shingle floating in the water, with a gigantic cheese box rising from its center: no sails, no wheels, no smokestack. No guns. What could it be?"
Lt. Catesby Jones - who had assumed command of the Virginia when Flag Officer Franklin Buchanan was wounded the previous day - recognized the outlandish craft immediately as the "Ericsson floating battery" reported on by Scientific American. But his men were still gaping as the Monitor's turret spun around, raised a gunport stopper and delivered a blast from one of its powerful 11-inch Dahlgren guns.
"You can see surprise on a ship just the same as you can see it in a human being," Monitor crewman Peter Truscott wrote.
"And there was surprise all over the Merrimac."
That surprise only mounted as the Virginia replied with its lethal forward pivot gun, then watched the shell explode with no apparent effect against the Monitor's 8-inch-thick iron turret.
Inside that armored shield, the Union gunners were even more amazed to have survived such a powerful blow uninjured.
"They all ducked and yelled - but nothing came through," said John V. Quarstein, author of the award-winning book "The Monitor Boys: The Crew of the Union's First Ironclad."
"Then they stood up and realized they were shot-proof."
One of history's greatest naval battles continued in much the same way for the next 4 hours, with the lumbering Virginia trying to evade its smaller, much more nimble opponent - and the Monitor stepping in to block every attack the rebel ironclad attempted on the hapless Minnesota.
But despite all the blows inflicted in this thunderous duel, it was remarkably short on blood and gore.
"They couldn't hurt each other, so they went around and around like boxers, with the speedier, more agile Monitor stopping the crawling Virginia at every turn," Holloway said.
"When you look at a diagram of the day's battle, it looks like a dance chart."
Inside the Confederate ship, the frustration mounted quickly as - again and again - the gunners missed the Monitor's maddeningly elusive gunports.
Soon, Jones found himself chiding a gun crew that had stopped its work.
"It is quite a waste of ammunition to fire at her," Lt. John R. Eggleston said.
"Our powder is precious, sir, and I find I can do the Monitor as much damage by snapping my fingers at her every 5 minutes."
Inside the Monitor though, the gunners struggled to keep their bearings as their turret spun.
That left Greene dependent on instructions from his captain - Lt. John L. Worden - who commanded the ship from a pilothouse 80 feet away.
"Had the revolving turret worked properly, they might have defeated the Virginia," Quarstein said.
"But their fire control was horrendous. They couldn't see what they were doing."
The Monitor came closest to victory when the Virginia ran aground, enabling Greene to send shot after shot into her side, testing the armor in every spot but the lightly plated sections of the waterline.
In desperation, the Confederates lashed down the safety valves and force-fed the boilers of their ship's old engines, pulling free from the shoal just when they were nearest destruction.
Frustrated by the powerlessness of their guns, both commanders finally turned to brute force, trying to ram their opponents.
The Monitor had just missed the Virginia's propeller when the rebel's stern pivot gun scored a direct hit on the Union pilothouse from point-blank range. Fire and smoke blasted through the narrow observation slot, blinding Worden and forcing Greene to break off.
Only the falling tide kept Jones from attacking the Minnesota. Firing a parting shot, he swung back toward Sewell's Point, alarmed by how much his vulnerable waterline had been exposed by the day's outlay of coal, powder and shot.
The rebel marauder was well underway when Greene returned, fired his own parting shot and pulled back to stand guard alongside the Minnesota.
Though both sides believed they were the victors, the real triumph of the day belonged to a new era of steam-powered mechanical weapons and iron shields.
"They weren't ships in the sense that everybody knew," Quarstein said.
"These were machines that fought like robots - and they came from a world of technological, industrial-age marvels that nobody had ever seen before."
VIEWS FROM THE BATTLE
"All manner of ships, sail and steam, were running out of Hampton Roads, leaving like a covey of quails." - USS Monitor Paymaster William F. Keeler, describing the vessels fleeing after the CSS Virginia's destruction of the USS Cumberland and USS Congress
"Certainly a grander sight was never seen. But it went right to the marrow of our bones." - USS Monitor executive officer Samuel D. Greene, describing the midnight explosion of the USS Congress, which had been set afire by the CSS Virginia
"(It was) such a craft as the eyes of a seaman never looked on before - an immense shingle floating in the water, with a gigantic cheese box rising from its center: no sails, no wheels, no smokestack. No guns. What could it be?" - Lt. James H. Rochelle of the CSS Patrick Henry
"Monitor has given up the fight." - CSS Virginia commander Catesby ap Roger Jones, seeing the Monitor pull off after the damage to its pilothouse
"Well, gentleman, you don't look as though you were just through one of the greatest naval conflicts on record." - Asst. Navy Sec. Gustavus Fox, greeting the Monitor's officers after the battle