Frantically loading and firing their rifled muskets, the Mississippi infantrymen defending the Stone Wall at Fredericksburg in Virginia about 11:05 a.m. on May 3, 1863, suddenly realized that all the .58-caliber lead bullets in the world would not stop the screaming, wild-eyed berserkers swarming toward them.

No matter how many comrades pitched onto the slope below Marye’s Heights, the blue-clad demons from Maine and Wisconsin kept coming.

And now they leaped the stone wall to hunt Confederates.

About 10:55 a.m. — just 10 minutes ago — officers and men of the 18th and 21st Mississippi infantry regiments figured they had the attacking Yankees licked. Standing behind the Stone Wall that bordered the Telegraph Road beneath Marye’s Heights just west of Fredericksburg, the gray- and butternut-clad Mississippians enjoyed a clear view east along the descending slope. Behind the infantrymen, the redoubts atop the heights bristled with cannons of the vaunted Washington Artillery from New Orleans.

In mid-December 1862, other Confederate infantryman jammed behind that same Stone Wall had slaughtered the Yankee divisions hurled against them. Today, Union Maj. Gen. John Sedgwick sent his VI Corps divisions to capture Marye’s Heights while the armies of Joseph Hooker and Robert E. Lee battled at Chancellorsville about 12 miles to the west.

When those damned Yankees charged up that slope, it would be a slaughter.

Or so every soldier in blue or gray thought that fine spring day.

Sedgwick had marched the VI Corps through a fog that partially obscured the full moon early Sunday morning. That same fog had lifted unexpectedly with daylight; Union soldiers realized that “beyond the Stone Wall and further up the heights was another line of rifle pits, which at the top were the enemy’s strongest works, consisting of redoubts and earthworks upon which engineering skill had been lavished,” said Lt. Charles A. Clark, adjutant of the 6th Maine. He was from Foxcroft.

Failing to outflank the Confederate defenders, Sedgwick decided to launch a frontal attack on Marye’s Heights. His veterans shuddered as “we made our dispositions to carry these heights by assault,” Clark said.

Sedgwick hurriedly planned a three-pronged assault. He ordered Col. Hiram Burnham of Cherryfield to form a “line of battle” that would become the southern prong; throwing forward five 5th Wisconsin Infantry companies as skirmishers, Burnham aligned the 6th Maine, 31st New York, and 23rd Pennsylvania Infantry by regiment from right to left (north to south) behind them. The 5th Wisconsin’s five remaining companies formed a thin reserve behind the three regiments.

The line of battle would hit the Telegraph Road along that section of the Stone Wall defended by the 18th Mississippi.

“The Sixth Maine in line of battle extended from a point a little to the left of the old Marye mansion where the plank road winds down the hill, over near to the present location of the national cemetery,” Clark recalled years later.

“We lay down behind a little crest which protected us from the enemy’s fire, and waited for the order of attack to be given,” he remembered.

Clark “was lying upon a blanket with Major [Joel] Haycock” of Calais. Confederate shells exploded nearby as the officers shared small talk.

All along the Union lines, friends shared farewells. Writing in “No Rich Men’s Sons,” author James Mundy related that in “Co. K, six comrades shook hands and vowed to reach the top or die trying. Of the six, only Private George Brown saw the crest of Marye’s Heights that day.”

With Burnham commanding the line of battle, Lt. Col. Benjamin Harris — a Machias lumberman — led the regiment this morning. Issuing “strict orders against firing a shot until the entrenchments” atop Marye’s Heights “were reached,” Harris ordered his men to “uncap their guns,” Clark said.

The 6th Maine boys would charge the heights armed only with the cold steel of their bayonets.

Bugles blared the charge at 11 a.m. Burnham ordered his regiments to attack, and “the men rushed forward at [the] double-quick, with arms a port,” Clark recalled.

The Wisconsin skirmishers stood and charged over the crest. Then the Pennsylvania, New York, and Maine boys stood and ran after the skirmishers. “Color Sergeant John Gray [of the 6th Maine] was the first man over the top,” Mundy wrote.

Behind Gray, Clark and Haycock “sprang to our feet, shook hands, each cried, ‘God bless you,’ and went forward with our line of battle,” Clark recalled.

Then the Mississippians loosed a deadly volley.

“The instant we reached the crest in front of us, Haycock was shot down and killed,” Clark said. “I saw him fall before the warmth of his pressure had left my hand, or his words had died out from my ears.”

Screaming “a terrific yell,” the Maine boys charged “across the ‘slaughter pen’” as “artillery and musketry poured a fire upon us which seemed to make the whole atmosphere hot and lurid,” Clark remembered.

“Shot, and shell, and grape, and shrapnel, plow and thin our ranks in vain,” he later wrote. “Red with blood is all the earth.”

Venting their fear and rage with a horrible keening, the 6th Maine boys shed bodies and limbs as they charged. “Men appear as men no longer, they are changed to warring fiends,” Clark said.

Another Union officer saw “Burnham’s line of blue on the green field” pause “as if to recover breath”; those regiments “slightly wavered.”

“The suspense was intense. Was it to be a victory or a defeat?” he asked.

A Maine surgeon watching the charge from elsewhere on the battlefield described how Burnham and his men “started forward, encountering a shower of bullets, grape, and canister, as soon as they rose above the slight knoll which had concealed him.”

He did not notice the 6th Maine waver during the attack, and Clark did not mention doing so. The 5th Wisconsin skirmishers went belly to earth sometime during the 300-yard charge. Their manhood questioned as the Maine boys hurled epithets while racing through the Wisconsin ranks, the Badger State soldiers leaped to their feet and ran intermingled with the Maine boys toward the Stone Wall.

Clark and Gray led them. The eyewitness surgeon saw the “brave color-guard bounding forward, then halting a moment while the men came up, then dashing forward again.

“Our flag — it was the flag of the Sixth Maine — [was] in advance of the others,” the surgeon cried.

Although “men fell on every hand,” the Maine boys could not be stopped, Clark remembered.

“What all the survivors did remember, and very clearly, was the berserk fury with which” the 6th Maine “approached the Stone Wall,” Mundy wrote in his book. “Above the din and racket of shellfire and musketry, the Mainers heard the demonic screams of their comrades.”

“As we reached the old Stone Wall my old schoolmate, Captain [Sewell] Gray, of Company A [and Exeter], was shot and killed instantly,” Clark said. “Further to the left,” Capt. Ralph Young from Co. G “also went down, to rise no more.”

A bullet skimming his head, Burnham reeled from his horse. He rose to his feet and joined the last desperate effort to reach the enemy.

Now the 6th Maine boys reached and vaulted the Stone Wall. Tradition places Color Sgt. Gray as the first man over the wall, but Clark could possibly claim that honor.

Leaping among the Mississippians, the Maine boys engaged in “a hand to hand fight at this point of short duration,” Clark reported.

“It was all bayonets and rifle butts, hand to hand combat at its most primitive. The 6th fought with such crazed ferocity that” a Confederate gunner with the Washington Artillery deployed on Marye’s Heights “later accused them of being under the influence of intoxicants,” Mundy wrote.

Despite some modern historians’ claims to the contrary, “it is not true that bayonets were never crossed during the war,” Clark stressed. “They were used at the Stone Wall by our men, and after the battle it was found, by actual count, that forty of the enemy had been bayoneted here.”

Union troops now breached the wall elsewhere. Confederate infantrymen went down fighting or scrambled up Marye’s Heights with Maine, New York, Pennsylvania, and Wisconsin soldiers in hot pursuit.

“We had now reached a point where the artillery in the works above us could not be depressed sufficiently to sweep through our ranks with grape and shrapnel,” Clark noticed. “Without firing a shot our line pushed ahead“ to attack “the last and strongest redoubts and fortifications at the summit.

“We pushed on with a shout of triumph, and carried the rifle pits higher up, which now swarmed with the enemy,” Clark said. “Here I saw Captain [John] Ballinger, of Company C, fall headlong, with a bullet through his brain. His curly head seemed to glisten with a halo of glory as we rushed passed him, still pushing forward to the enemy’s last entrenchments.”

Atop the heights, Confederate troops “fought with a frenzy equal to our own, and with a grim determination to hold their position to the last,” Clark recalled.

Now Burnham’s men capped their rifled muskets and shot their enemies, those not already bayoneted or surrendered. Suddenly Harris stood atop the parapets and thrust aloft “the 6th Maine’s flag on a shattered staff,” Mundy wrote.

Color Sgt. John Gray had carried that flag up Marye’s Heights, where a concussion — probably caused by a Confederate rifle butt — dropped him beside Harris.

“One single color (that of the 6th Maine) never for one second faltered until the very crest of the heights was gained and it became a sign of victory,” recalled Capt. Richard Halstead, a Union officer who witnessed the charge.

Clark reported that the 6th Maine captured “seven guns of the celebrated Washington Artillery, and numerous prisoners.

“Our success was glorious, but we had paid for it dearly,” he wrote afterwards. “In the less than five minutes which elapsed from the time we started upon the charge until our flag floated in victory over the heights which had been thought impregnable, we had lost more than one-third of our officers and men killed and wounded.”

Estimates vary between 400 and 500 the number of 6th Maine boys who charged Marye’s Heights that sunny Sunday morning. James Mundy cited 169 casualties suffered by the regiment.

As for Charles Clark, he would survive the war. Many comrades who helped capture Marye’s Heights would not.