The Battle of Cold Harbor occurred as part of General Ulysses S. Grant's Overland Campaign, aimed at defeating Robert E. Lee's Confederate Army in Virginia. Grant had undertaken a series of direct engagements against Lee, focusing on attrition and rapid movement. Cold Harbor, located just east of the Chickahominy River, became a critical moment in the campaign, commencing on May 31 and escalating until early June. Lee's troops had established strong defensive works, which positioned them advantageously against the advancing Union forces.

Over the course of the battle, Union troops launched assaults against entrenched Confederate positions. The Union forces, numbering around 100,000, faced approximately 55,000 Confederate soldiers. The engagement was characterized by the Union’s poorly coordinated frontal assaults, which were met with devastating artillery fire and small arms from Lee's entrenched troops. The most infamous event of the battle was a frontal assault on June 3rd, which resulted in heavy Union losses and became a symbol of the brutality of the war.

Cold Harbor exemplified the grim realities of the Civil War, highlighting the effectiveness of trench warfare and the challenges of direct assaults against fortified positions. Grant later claimed that he regretted his decision to assault, noting the heavy losses endured by his troops. This battle, while a tactical victory for the Confederates, also underscored the growing futility of such engagements, leading to a shift in strategy for both sides as the war progressed.