The facts of the Battle of Cold Harbor, which took place May 31 and June 12 1864, are stark and straight forward. The implications, especially regarding future conflicts, were not well understood at the time and are only apparent in retrospect.
The Civil War Trust recounts the battle thus:
“On May 31, Maj. General Sheridan’s cavalry seized the vital crossroads of Old Cold Harbor. The following morning, Sheridan was able to repulse an attempted repossession by Confederate infantry. Confederate reinforcements soon arrived and clashed with the Union Sixth and Eighteenth Corps when they reached Cold Harbor that evening. By June 2, the armies had formed a seven-mile front that extended from Bethesda Church to the Chickahominy River. General Grant was poised for a major assault to General Lee’s right flank and cut off the Confederates off from Richmond, but when Maj. General Hancock’s Second Corps arrived after a midnight march too fatigued to support the Union left flank, the operation was postponed until the following day. This fatal delay gave Lee’s troops time to build an impressive line of trenches. At dawn June 3, the Union Second, Sixth, and Eighteenth Corps, followed later by the Fifth and Ninth Corps, assaulted along the Bethesda Church-Cold Harbor line and were slaughtered at all points. Grant pulled out of Cold Harbor after nine days of trench warfare and continued to try to flank Lee’s army at Petersburg.”
The reader will notice the phrase “trench warfare” in the account, a foreshadowing of the bigger blood baths that were to occur 50 years later in the fields of France. By the Civil War, military technology had reached the point that the overwhelming advantage on the battlefield had gone to the defender. Infantry were equipped with muzzle loaded Springfield and Enfield rifled muskets that had a range of 500 yards and used smokeless powder. Artillery had also achieved longer ranges and more rapidity of fire.
Soldiers on both sides of the Civil War had already been demonstrated how frontal assaults could devolve into blood baths. At Fredericksburg, Union infantry were slaughtered in rows as they made futile assaults on Confederate positions. At Gettysburg, on the third day, it was the Confederacy’s turn as Pickett’s Charge collapsed into bloody ruin.
Add to that the protection of trenches and it had become apparent that the tried and true battlefield tactics that had been taught at military academies since Napoleon had become obsolete. Grant was lucky that he had room to disengage and move on rather than be locked in position with Lee. However he was to experience more miserable trench warfare during the months long siege of Petersburg.