At Antietam, the corps was held in reserve aside from Col. William Erwin's brigade, which participated in the storming of Bloody Lane.

Up to this point, the entire corps had never fought a major engagement as a whole, only pieces of it participating in the battles on the Peninsula and Antietam.

Their chance finally came when Maj. Gen. Joseph Hooker took the Army of the Potomac to Chancellorsville he left the VI Corps in front of Fredericksburg, which was still held by a strong force of the enemy.

Gen. Alexander Shaler's Brigade was sent into action as a support to the XII Corps on the right flank; several casualties also occurred in Brig.

During the pursuit of Robert E. Lee's army after Gettysburg, the Vermont Brigade was engaged at Funkstown, Maryland, where this one brigade, drawn out in a skirmish line of over a mile in length, alone and unassisted, repelled a determined attack of a vastly superior force, which in massed columns charged this skirmish line repeatedly.

It was a success that resulted not only in a victory, but in the capture of a large number of prisoners, small arms, artillery and battle flags from the division of Major General Jubal Early.

In the Mine Run Campaign the divisions were commanded by Generals Wright, Howe, and Henry D. Terry, but were not in action to any extent.

In the battles of the Wilderness and Spotsylvania of the Overland Campaign, the VI Corps encountered the hardest contested fighting of its experience.

General Sedgwick was killed by a sniper's bullet at Spotsylvania on May 9, which caused great distress to the soldiers of the corps, who loved and admired their "Uncle John".

On May 10, Col. Emory Upton led a storming party of twelve picked regiments selected from the VI Corps; they carried the Confederate works in the "Mule Shoe" after a hand-to-hand fight in which bayonet wounds were freely given and received.

On May 12, the entire corps fought at the "Bloody Angle", where the fighting was among the closest and deadliest of any recorded in the Civil War.

Early's invasion of Maryland necessitated a transfer of troops to confront him, and the VI Corps selected for that duty in the Valley Campaigns of 1864.

This division took part in the Battle of Monocacy on the following day, and, although unable to defeat Early, checked his advance on Washington, D.C., giving the defenses their time to organize.

The other two divisions embarked on July 10 and, landing at Washington, attacked Early, whose advance had reached Fort Stevens, within the city limits.

Maj. Gen. Philip Sheridan was placed in command of the Army of the Shenandoah, which was composed of the VI, VIII, and XIX Corps, and its campaign in the Valley was a memorable one by reason of the victories at Third Winchester, Fisher's Hill, and Cedar Creek.

In December 1864, the VI Corps returned to the Army of the Potomac in the Petersburg trenches, built their winter quarters, and went into position near the Weldon Railroad.

A Confederate attack on the corps as it crossed the creek was repulsed with support from the artillery, and the counterattack broke Lt. Gen. Richard S. Ewell's line.

Major General George Washington Custis Lee was forcibly captured on the battlefield by Private David Dunnels White of the 37th Massachusetts Regiment.