The US Civil War has no shortage of horrific and bloody battles. The Civil War featured some of the most devastating battles in American history. There were multiple battles that racked up more than 10,000 casualties per side. Through all of this carnage, there was one major battle that had the highest percentage of casualties overall.

When making a guess for the battle with the highest casualty rate, many people offer familiar names like Gettysburg, Shiloh, Antietam, or Fredericksburg. But it was none of those.

The bloodiest battle of the Civil War in terms of sheer percentage of soldiers taken out of commission was fought in central Tennessee between Generals William Rosecrans of the Union and Braxton Bragg for the Confederacy.

The Battle of Stone’s River

The battle was fought over three days, stretching from December 31st, 1862, through January 2nd, 1863. The Union army under Rosecrans had marched out from Nashville to give battle to Braxton Bragg’s army lurking near Murfreesboro. Lincoln wanted Rosecrans to dislodge Bragg and force him away from Nashville and into southern Tennessee.

Unbeknownst to most, eastern Tennessee was strongly pro-Union. There were many unionists spread throughout the Appalachian region of the state, and Lincoln had been desperate to “liberate” these Americans and bring them back into the fold of the Union.

If Rosecrans could smash the Confederate army around Nashville, they could secure eastern Tennessee and use it as a base to clear the rest of the state and push on towards Georgia and South Carolina.

When Rosecrans and Bragg began maneuvering to get around one another, each chose to target the other’s right flank.

On the morning of December 31st, Bragg ordered his army to attack in the predawn hours. The surprise attack shocked the Union army and led to numerous surrenders and POWs being taken before breakfast. The morning assault gave way to a ferocious battle that raged for the remainder of the day.

The terrain around Nashville was cold, hilly, and rocky. There were ample places for brigades to hunker down and throw out withering fire against exposed enemy positions.

The initial assault pushed the Union army back and forced them to constrict their lines, but the new defensive position was a strong one. Bragg could not dislodge Rosecrans from his newly formed lines. Despite the failure to force the Union army to break, Bragg believed he had won a great victory. The casualty numbers were immense on both sides.

General Bragg wired a message to President Jefferson Davis at the conclusion of the day, writing:

The enemy has yielded his strong position and is falling back. We occupy [the] whole field and shall follow him. … God has granted us a happy New Year.

Bragg’s assessment was premature and overly optimistic. Come New Year’s Day. It would become clear that Rosecrans had not retreated as Bragg predicted but had simply reinforced the lines he had established the previous day.

After debating about what to do on January 1st, Bragg elected to attack Rosecrans’s lines on January 2nd with disastrous results. The rebels were repulsed by heavy artillery fire and sharpshooting with heavy casualties.

Failing to dislodge Rosecrans and fearing Union reinforcements coming from Nashville, Bragg opted to retreat. Both sides lost an enormous number of soldiers in the hard fighting. Rosecrans’s army would not be able to march for another six months.

By The Numbers

The Battle of Stone’s River, or the Battle of Murfreesboro as it is sometimes called, produced 24,645 total casualties.

The Union suffered 12,906 casualties.

The Confederacy suffered a nearly equal number with 11,793 casualties.

The total number of troops engaged during the fighting was 78,400. That put the total casualty rate at 31.4%. Nearly one in three men at Stone’s River could not go on to fight afterward.

That figure, 31.4%, remained the highest casualty rate of the entire war beating out Antietam, Gettysburg, and Chancellorsville.

Breakdown of Casualties

Dead: 2,979

Wounded: 15,523

Missing or Captured: 6,115

Four generals were killed in the carnage, two from each side. Generals Rains and Hanson lost their lives fighting for the Southern cause. Generals Kirk and Sill died for the Union cause.

Conclusion

The high number of casualties had a big effect on both Rosecrans and Bragg. Rosecrans took months to recover his army and his fighting ability. Afterward, the previously successful general fell into a pattern of caution and fear. Braxton Bragg’s failure to press his initial success and a large number of casualties caused his subordinates to distrust him. Bragg would go on to battle insubordination, bitterness, and low morale in the coming months as his Army of Tennessee languished.

Bragg would eventually be forced out of Tennessee after a disastrous defensive campaign that saw him lose Chattanooga and Knoxville. Rosecrans would eventually be removed from command after a series of indecisive battles. Rosecrans was replaced by Generals Grant and Thomas, who came and took over the situation from him following the fall of Vicksburg in the summer of 1863.