Union General Ulysses S. Grant launched a major offensive against Confederate forces commanded by General Robert E. Lee near Richmond, Virginia in late May 1864.

The battle resulted in massive Union casualties—approximately 7,000 killed, wounded, or missing—compared to roughly 1,500 Confederate losses, making it a devastating defeat for the North.

Grant's repeated frontal assaults against well-fortified Confederate positions failed to break through Lee's defensive lines, resulting in a stalemate rather than the decisive victory Grant had sought.

Grant later called the battle his greatest regret of the war, acknowledging that the heavy losses achieved nothing of strategic value.

The Battle of Cold Harbor took place over two weeks in spring 1864 as part of Grant's Overland Campaign, his major push to defeat Lee's Army of Northern Virginia and capture Richmond. Grant had been promoted to commanding general of all Union armies and was determined to end the war through aggressive action. He pursued Lee's army across Virginia, and the two forces clashed at a crossroads known as Cold Harbor, just northeast of Richmond.

Despite warnings from some of his officers, Grant ordered a series of frontal assaults on June 3rd against Confederate entrenchments. The attacks were poorly coordinated and met with withering rifle and artillery fire. Soldiers on both sides knew the assaults were futile—some Union soldiers reportedly pinned their names to their uniforms before attacking, expecting to die. After three days of fruitless fighting, Grant called off the offensive and the armies settled into a stalemate.

The battle illustrated the brutal calculus of Civil War combat: superior Union numbers could not overcome the advantage of defensive fortifications and determined Confederate resistance. Though Grant's overall campaign eventually put Lee under increasing pressure, Cold Harbor demonstrated the limitations of frontal assaults in trench warfare and the terrible human cost of attrition. Grant's candid regret about the battle showed his willingness to confront his own mistakes, a quality that distinguished him as a military leader.