The 6th, recruited from the state at large, was mustered into the U. S. service for three years under Colonel Nathan Lord, Jr., the son of the Dartmouth College president Nathan Lord,[2][3][4][5] at Montpelier, October 15, 1861, and immediately ordered to Washington, where it arrived on October 22.

[note 1] The command remained at this post during the winter and broke camp on March 10, 1862, for George B. McClellan's Peninsula Campaign.

[2] After the battle, it went into winter quarters at White Oak Church, where it remained, with the exception of the "Mud March," until camp was broken for the Chancellorsville movement in the end of April 1863.

The 6th participated in the capture of Marye's Heights in the Second Battle of Fredericksburg and then were prominent in the fighting at Salem Church.

[6] Like most of VI Corps, the regiment and its brigade were held in reserve during the Battle of Gettysburg, holding a flank guard position behind Big Round Top, losing only one man wounded.

After the Gettysburg Campaign, the 6th saw elements of their brigade were sent to help quell the draft riots in New York City while they remained in Virginia, fighting at Funkstown later in the summer.

That same month, the Army of the Potomac, under the overall supervision of Lt. Gen. Ulysses S. Grant, began its spring offensive (the Overland Campaign) towards Richmond.

Ordered to retreat, the 6th and its brigade were given time to fall back to new breastworks by an opportune bayonet charge by the 5th Vermont.

[8] After the Wilderness, over the weekend of 7–8 May, the U.S. forces moved south to Spotsylvania Court House, where Lee's army had entrenched.

Early in the battle, on May 9, the brigade, defending barricades forward of the rest of the Union Army, were ordered to retreat and spike their supporting artillery field pieces before the Confederates overran them.

[8] The next day, Tuesday, May 10, the 6th Vermont was within the brigade as it led Upton's successful late afternoon assault on the west side of the "Mule Shoe Salient", a protruding network of trenches in the center of the Confederate lines.

The regiment moved southward as the army won victories at Winchester and Fisher's Hill.

[9] On Wednesday, October 19, At the Cedar Creek, Early launched a surprise attack against Sheridan's army and the regiment, and its brigade covered the Union army's temporary retreat, prior to Sheridan's counterattack and decisive victory.

In the final phase of the siege, the 6th was in the van of the First Vermont Brigade's successful break-through attack on the earthworks defending the city, on Monday morning of April 2, 1865.

[9] After the surrender of Lee's army on Sunday, April 9, the 6th Vermont took up the initial occupation duties in and around Richmond.

At home, many former members of the regiment joined fraternal veterans organizations such as the Grand Army of the Republic and the Military Order of the Loyal Legion of the United States to enact legislation to support veterans and their families, often and held reunions recount their service in the 6th Vermont Infantry.

[9] Through its service, the commanders were: The staff officers were: Its assignments are as follows:[8][10][11][12] The official list of battles in which the regiment bore a part:[7][13][14][5] The 6th Vermont's original strength was 966.