The 21st Massachusetts Volunteer Infantry Regiment lost 11 officers and 148 enlisted men killed or mortally wounded and 2 officers and 89 enlisted men to disease during the Civil War. The regiment is honored by a monument at Antietam near Burnside’s Bridge.

1861
July 19 –
August 19
Organized at Worcester under Colonel Augustus Morse, Lieutenant Colonel Maggi and Major William S. Clark.
August 23-25 Moved to Baltimore, Md.,
August 29 To Annapolis, Md. and duty there
1862
January 6 Attached to Reno’s 2nd Brigade, Burnside’s Expeditionary Corps
January 6-
February 7
Burnside’s Expedition to Hatteras Inlet
February 8
Battle of Roanoke Island

Commanded by Lieutenant Colonel Maggi, the regiment lost 5 enlisted men killed and 2 officers and 37 enlisted men wounded

February 9 –
March 11
At Roanoke Island
February 28 Major Clark was promoted to lieutenant colonel.
March 11-13 Moved to New Berne
March 14 Battle of New Berne
April Attached to 2nd Brigade, 2nd Division, Dept. of North Carolina
April 17-19 Expedition to Elizabeth City
April 19 Battle of Camden, South Mills
April 20 –
July 6
Duty at New Berne
May 15 Colonel Morse resigned. Lieutenant Colonel William S. Clark was promoted to colonel.
May 17 Expedition to Pollocksville to relief of 2nd Maryland
July Assigned to 2nd Brigade, 2nd Division, 9th Army Corps, Army of the Potomac
July 6-9 Moved to Newport News, Va.
August 2-4 To Fredericksburg
August 12-15 March to relief of Gen. Pope
August 16 –
September 2
Pope’s Campaign in Northern Virginia
August 28
Battle of Groveton
August 29-30
Second Battle of Bull Run
September 1
Battle of Chantilly

The battle was fought in a blinding thunderstorm. After running into Confederate positions in a woods and taking casualties, the regiment was ordered to the center of the line by General Kearny. The skirmishers quickly came under heavy fire and Colonel Clark halted his advance. General Kearny rode up and demanded the advance resume. When told that the woods ahead was full of rebels he refused to believe it and rode forward to prove he was right, only to be shot down.

The Confederates then attacked, nearly surrounding the 21st Massachusetts. After everyone around him was shot Colonel Clark moved forward through the Confederate attackers, taking three bullet holes in his clothes but evading capture. He was missing and reported dead, with his obituary published in his hometown newspaper and his wife telegraphing to ask that his body be found and returned to Massachusetts. Four days later he returned to the regiment, reassuring his wife he would return his body in person.

September-
October
Maryland Campaign
September 14
Battle of South Mountain
September 16-17
Battle of Antietam

The regiment was commanded by Colonel William S. Clark and totaled about 150 men.

From the monument on the Antietam battlefield:

The following Comrades were killed near this bridge:
2nd Lieut. Henry C. Holbrook

Co. D  Priv. Wm. B. Boynton
”     ”     ”     Amos S. Eastman
Co. E  Corp. Henry K. Buss
”    ”   Priv. Geo. T. Bigelow
Co. G  Corp. Jas. S. Stratton
”    ”   Priv. Daniel Daley
”     I  Priv. Chas. Leonard
Co. K 1st Sergt. Geo. W. Davis
”    ”   Priv. Chas. S. Brigham
and 35 other wounded

From the War Department marker for Ferrero’s Brigade at Burnside’s Bridge:

On the morning of the 17th Ferrero’s Brigade was in position about a half mile northeast of this point on the Rohrback Farm. About 9 A.M. it moved to the left and, after several changes of position, was ordered to carry the bridge. The 51st Pennsylvania and the 51st New York were formed under cover of the hill overlooking this point; skirmishers were thrown forward to the stone fence above the bridge and behind fences and trees along the stream below it; and, under cover of the fire from the Federal Artillery, the two Regiments charged down the hill, carried the bridge and formed, under cover of the bluff, in the road beyond it. The 35th Massachusetts, closely supported by the 21st Massachusetts, followed and ascended the bluff on the right where, later in the day, it was joined by the remainder of the Brigade and led the advance to the Otto farm lane, where it became severely engaged and lost heavily in killed and wounded.

Late at night the Brigade was relieved by Welsh’s Brigade of Willcox’s Division and fell back to the banks of the Antietam.

From the War Department marker for Ferrero’s Brigade on Branch Avenue:

After Ferrero’s Brigade carried the stone bridge it formed under cover of the high ground north of it. Nagle’s Brigade formed on its left. Willcox’s, Scammon’s and Rodman’s Divisions formed in advance of them and moved on Sharpsburg. On the repulse and retirement of the three Divisions, Ferrero and Nagle advanced to check Confederate pursuit. The left and center of Ferrero’s Brigade halted under cover of the crest of the ridge beyond the ravine, the right (35th Massachusetts) continued its advance to Otto’s lane, 270 yards distant, and engaged the Confederates posted on this line behind the stone walls right and left of it and in the 40 acre cornfield south. The engagement continued into the night, Ferrero’s Brigade suffering much loss, the principal part of which fell to the 35th Massachusetts, which had 214 officers and men killed and wounded.

September 17 – October 27 The 21st Massachusetts was at Pleasant Valley, Maryland. Colonel Clark was sent home for “a minimum of 30 days” with “intermittent fever, accompanied with diarrhea, emaciation and general debility.”
October 27-
November 17
Movement to Falmouth, Va.
November 15 Warrenton, Sulphur Springs
December 12-15
Battle of Fredericksburg
1863
January 20-24 “Mud March”
January 25 At Falmouth
February 19 Moved to Newport News, Va., and duty there
March 26-April 1 Moved to Covington, Ky.
April Attached to 2nd Brigade, 2nd Division, 9th Army Corps, Dept. of the Ohio
April 1-5 At Paris, Ky.
April 6 At Mt. Sterling
April 22 Colonel Clark resigned due to the “reduced condition of my regiment and the belief that I can be more useful at home than in the army under existing circumstances.”
June Unassigned, 1st Division, 23rd Army Corps, Dept. of the Ohio,
then 1st Brigade, 1st Division, 9th Army Corps
July 6 At Camp Nelson
September 12-20 March to Knoxville
October Attached to 1st Brigade, 2nd Division, 9th Army Corps, Dept. of the Ohio
October 22-
November 4
Operations in East Tennessee
November 4-December 23 Knoxville Campaign
November 17-
December 4
Siege of Knoxville
December 16 Campbell’s Station
December 5-29 Pursuit of Longstreet
December 29 Reenlisted
1864
January to March Veterans absent on furlough
April Moved to Annapolis, Md. and attached to 2nd Brigade, 1st Division, 9th Army Corps, Army of the Potomac
May-June Campaign from the Rapidan to the James
May 5-7
Battle of the Wilderness
May 8-21
Battle of Spotsylvania Court House
May 10 Ny River
May 12 Assault on the Salient
May 23-26 North Anna River
May 24 Ox Ford
May 26-28 Line of the Pamunkey
May 28-31 Totopotomoy
June 1-12
Battle of Cold Harbor
June 1-3 Bethesda Church
June 16-18
First Assault on Petersburg
June 16-
October 21
Siege of Petersburg
July 30
Mine Explosion, Petersburg
August 18 Non-Veterans left front
August 30 Non-Veterans mustered out
August 18-21 Weldon Railroad
September Attached to 2nd Brigade, 1st Division, 9th Army Corps
September 29-
October 2
Poplar Springs Church, Peeble’s Farm
October 21 Veterans and Recruits transferred to 36th Massachusetts Infantry