The second battle of Bull Run, fought Aug. 29, 1862. (Library of Congress Prints and Photographs Division)

The hardened armies that would meet at the Second Battle of Manassas in late August 1862 had none of the naive enthusiasm of the men who a year earlier had joyously marched to the fields around Bull Run for a battle they believed would put a quick end to the young war between the states.

If the stunning Confederate victory at First Manassas in July 1861 had shown that a long, hard road lay ahead in this war, Second Manassas would show how bloody it would be.

The nation had been shocked by the toll at the First Battle of Manassas, which saw more than 5,000 casualties, including nearly 900 dead — the bloodiest battle in American history, to that point.

But as the Civil War stretched into its second year, the battles had become deadlier. The armies had grown much larger, the officers more competent, their tactics more proficient. The weapons were deadlier — more rifles with better accuracy and more precise artillery. As much as anything, it was this: The men had become expert at killing and remorseless about it.

In the western theater in April, Union troops under Gen. Ulysses S. Grant clashed with a large Confederate force at Shiloh, leaving more than 20,000 casualties, an unprecedented number. That grim mark was about to be matched on the familiar swales of farmland around Bull Run, 26 miles west of Washington.

‘An ungovernable mob’

In the summer of 1862, as Union Gen. George McClellan’s Peninsula Campaign bogged down in front of Richmond, President Abraham Lincoln pinned his hopes on another commander who might bring victory. Gen. John Pope, who had achieved modest success in the west, was given command of the newly created Army of Virginia.

Pope quickly earned the enmity of his new army in his first address to the troops when he snidely suggested they lacked the courage of the western soldiers. But Pope had something McClellan lacked: an aggressive streak. The new commander was determined to seek out and destroy the Confederate Army.

In early August, McClellan was ordered to send his troops to Northern Virginia, where they would unite with Pope’s army and create an overwhelming force that could crush Robert E. Lee’s Army of Northern Virginia. But McClellan, jealous of Pope’s new prominence, delayed his departure for 10 days.

In the division of the Union armies, Lee saw opportunity. Lee would defeat Pope before he could be reinforced.

After several weeks of maneuvering, Lee’s and Pope’s armies were poised across from each other on opposite sides of the Rappahannock River. Lee developed a bold plan to split his own army.

Gen. Thomas J. “Stonewall” Jackson — his nickname earned by his tenacious stand at First Manassas — would take one wing around Pope’s right flank to get behind the enemy. The second wing, under Gen. James Longstreet, would stay at Pope’s front — but not for long. Once Pope turned his troops around to chase Jackson, Lee and Longstreet would follow Jackson’s path to reunite the army and try to inflict a decisive defeat on the Union force. The Confederate plan carried great risk, presenting Pope with an opportunity to destroy each wing of Lee’s army in succession.

On Aug. 25, Jackson launched his 24,000 men on one of the war’s great marches, covering more than 50 miles in 34 hours. At dawn Aug. 26, his lead elements passed through the Bull Run Mountains at Thoroughfare Gap and into the rear of Pope’s army.

Jackson had an open path to Manassas Junction, the critical railroad hub that gave the ground around Bull Run such strategic importance. Jackson’s men, lean, hungry and wide-eyed, fell upon an enormous, undefended federal depot, with warehouses and boxcars filled with rations, helping themselves to cigars and whiskey and wolfing down lobster accompanied by Rhine wine.

“Just imagine about 6000 men hungry and almost naked, let loose on some million dollars worth of biscuit, cheese, ham, bacon, messpork, coffee, sugar, tea, fruit, brandy, wine, whiskey, oysters, coats, pants, shirts, caps, boots, shoes, blankets, tents, etc.,” wrote a horrified chaplain from Louisiana. “I saw the whole army become what appeared to me an ungovernable mob.”

Union Brig. Gen. George Taylor led more than 1,000 New Jersey troops to the scene, confidently expecting to scatter some Confederate raiders. Instead, they met an explosion of fire from Jackson’s army. A quarter of the Union men were lost, and the mortally wounded Taylor urged his officers “for God’s sake to prevent another Bull Run.”

Pope saw no such danger. He withdrew his 66,000-man army from the Rappahannock and sent them northeast to hunt down Jackson’s army. “We shall bag the whole crowd,” he declared.

But Jackson was not trapped or trying to escape, as Pope assumed. He moved a few miles northwest and took up a strong position on Stony Ridge, hidden in woods above the Warrenton Turnpike — modern-day Route 29 — along the likely avenue of Union approach. Late in the day, Aug. 28, a Federal column came marching east on the turnpike, in front of his concealed troops.

To the horror of his staff, Jackson rode across broom sedge fields to within musket range of the passing Union troops, who paid no mind to the lone rider. Satisfied that a large Federal force was within his sights, Jackson rode back to the Confederate line and issued orders to his officers: “Bring out your men, gentlemen.”

The ensuing fight at Brawner’s Farm — which marked the beginning of Second Manassas — was one of the most brutal of the war. It pitted one of the best Union units — Wisconsin and Indiana troops soon known as the Iron Brigade — against the most storied Confederate outfit: the Stonewall Brigade.

Moving up the slope into withering fire, the Union troops almost overran the Confederates, but when the fighting stopped after dark, the Federals had been held off. Almost one-third of the troops engaged had been killed or wounded in the bloody standoff.

“My God, what a slaughter,” wrote Pvt. George Fairfield of the 7th Wisconsin.

But worse was to come.

‘Like chaff before the tempest’

On the morning of Aug. 29, Jackson placed his troops along a stretch of unfinished rail bed roughly parallel to the turnpike, a well-protected position. Despite the heavy losses, Jackson was sanguine. He knew Longstreet was on his way.

Several times, the Union troops briefly breached the Confederate line, but each time they were pushed back. By the end of the day, four massive but disjointed Union assaults had failed to break through Jackson’s left flank, leaving bodies piled before the railroad bank.

“My brave lads were dashed back before the storm of bullets like chaff before the tempest,” reported Brig. Gen. Robert Milroy, a Union brigade commander.

An even greater danger lay off Pope’s exposed left flank, where Longstreet’s wing was taking position, leaving the Union army squeezed inside a giant vise.

Night fell and fighting ended for the day with Pope still unconcerned about the threat, despite warnings from commanders in the field.

Behind Confederate lines, Jackson listened to a lengthy casualty report without comment. Some believed the general was beyond remorse a year into the war. But when surgeon Hunter H. McGuire disclosed that among the dead was 19-year-old Willie Preston, the gentle-natured son of close friends from Lexington, Jackson’s muscles twitched and his eyes glowed. “He gripped me by the shoulder till it hurt me, and in a savage, threatening manner asked why I left the boy,” McGuire recalled. “In a few seconds he recovered himself, and turned and walked off into the woods alone.”

Hurling rocks at Union troops

Saturday, Aug. 30, the final day of the battle, dawned hot, dry and quiet. Though Pope had finally recognized Longstreet’s arrival, he ignored the threat and prepared to attack. He sent a wire to Washington reporting the enemy had been “driven from the field” and his expectation that a glorious victory was at hand.

It was almost 3 p.m. when a single Union cannon fired a shot, the attack signal for 12,000 Union soldiers in 37 regiments, lined up in assault formation that stretched more than a mile. In the desperate close-quarters fighting that ensued along the railroad bank, Confederates who had expended all of their ammunition were reduced to hurling rocks at the Union troops.

With his entire line in danger, Jackson sent a message to Lee asking for reinforcements. Now Longstreet opened up with 18 cannons sighted on the open ground where the Federals were advancing. Next he unleashed his five divisions, 25,000 soldiers, stretching nearly a mile and a half. It was the largest single mass assault of the war. With frightful screams, the rebel troops swept forward through fields, streams and woods.

Two New York regiments of Zouaves, who wore gaudy uniforms with baggy red trousers and tasseled fezzes modeled after the French, were the first to pay the price, overrun by Gen. John Bell Hood’s Texans. In 10 minutes, the 5th New York lost more men than any regiment would in any other battle of the war — 124 killed and 223 wounded out of 490. To one of Hood’s men, the bodies of the Zouaves sprinkled across the slope gave the appearance of “a Texas hillside when carpeted in the spring by wild flowers of many hues and tints.”

At last, Pope grasped his ghastly miscalculation and rushed to save his army. He sent troops to occupy the strategic high ground at Henry Hill. A brigade of Ohioans, reinforced by artillery and followed by others, bought time for their comrades with a stand on Chinn Ridge, which lay between Henry Hill and the advancing Confederates. They slowed the Confederate advance, buying 90 precious minutes, but at fearful cost.

Capt. Mark Kern, the commander of a Pennsylvania battery, was one of many who sacrificed his life. “I promised to drive you back, or die under my guns, and I have kept my word,” he told the Texans.

Henry Hill was secured, enabling Pope’s army to retreat in darkness across Bull Run and eventually to the safety of Washington’s fortifications.

“We are whipped again, I am afraid,” Lincoln sadly told his secretary, John Hay.

Second Manassas left 3,300 dead, more Americans than have died in a decade of war in Afghanistan. Although it lies just minutes from Interstate 66, the rolling landscape of Manassas National Battlefield Park has a peaceful beauty far removed from 150 years ago, when the mangled and bloody remains of thousands of young men lay in fields and streambeds, on hill slopes and in piles at the foot of the unfinished railroad grade.

Never again would Lee and the Army of Northern Virginia come so close to destroying a Federal army as it did at Second Manassas.

But the Federal army had escaped, and within days, Lee made the fateful decision to invade Maryland. Less than three weeks later, his troops would meet the Union army at Antietam, where a sad new standard of American bloodshed would be set.

Sources: National Park Service; U.S. Army Center of Military History; “The Second Battle of Manassas,” by A. Wilson Greene; “Return to Bull Run,” by John Hennessy; “The Battle of Second Manassas,” by Joseph W.A. Whitehorne; “Stonewall Jackson,” by James I. Robertson Jr.; “The Civil War,” by Shelby Foote; “Battle Cry of Freedom,” by James McPherson; “Team of Rivals,” by Doris Kearns Goodwin.