Battle of Cold Harbor: The 20-Minute Assault That Caused 7,000 Union Casualties

The Battle of Cold Harbor (31 May to 12 June 1864) was the final major engagement of the Overland Campaign, the large-scale Union offensive into Virginia in the final year of the American Civil War (1861-1865). It marked a devastating defeat for the Union Army of the Potomac, which lost around 7,000 men in just 20 minutes during an assault on 3 June. The battle also saw the transition from the swift maneuverings and bloody battles of the Overland Campaign to the static trench warfare that would characterize the final phase of the war, at the Siege of Petersburg (June 1864 to April 1865).