On June 3, 1864, Ulysses Grant ordered a frontal assault on entrenched Confederate positions at Cold Harbor, Virginia. In less than an hour, the Union Army suffered approximately 7,000 casualties. It was the most lopsided tactical defeat of Grant's career — and the battle he later said he regretted most.

The Setup

Grant had been driving Lee's Army of Northern Virginia southward for a month in the Overland Campaign. The battles of the Wilderness, Spotsylvania, and North Anna had all ended in Confederate tactical holds, but at a cost: Lee's army was steadily shrinking, unable to replace its losses. Grant's approach was unrelenting. He moved south after each engagement, forcing Lee to follow.

By late May, both armies had settled into defensive lines north of the Chickahominy River near a crossroads called Cold Harbor, seven miles northeast of Richmond. Lee's engineers had constructed formidable earthworks during a brief pause in fighting — deep trenches with forward traverses that allowed interlocking fields of fire.

The Assault

Grant ordered the attack for June 3. Corps commanders had doubts but proceeded. As the Union troops advanced in the pre-dawn, Confederate defenders waited behind carefully prepared positions. When the assault began at 4:30 a.m., the lead Union regiments were hit from front and flanks simultaneously.

The assault columns broke within minutes. Veterans who had survived the Wilderness and Spotsylvania stopped, went to ground, and began digging with their bayonets and tin cups. Some units advanced no more than a hundred yards. Most of the casualties occurred in the first eight minutes.

Grant recognized the disaster almost immediately and called off further attacks. He later wrote in his memoirs: "I have always regretted that the last assault at Cold Harbor was ever made."

What It Meant

Cold Harbor did not alter the strategic picture significantly. Lee was still losing men he could not replace. Grant was still grinding southward. Within two weeks, the Union Army would perform its remarkable crossing of the James River and begin the Petersburg siege.

But Cold Harbor illustrated the limit of direct assault against prepared positions, a lesson the Civil War kept teaching and commanders kept forgetting. The rifles of 1864, accurate at 300 yards, made frontal assaults against dug-in defenders prohibitively expensive. The tactics of the Mexican War — quick, aggressive frontal attacks that routed defenders before they could concentrate — had become suicidal.

Grant learned the lesson. He never made that kind of attack again.