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.

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
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 29 Battle of Groveton
August 30 Battle of Bull Run
September 1 Battle of Chantilly
Maryland Campaign
September 14 Battle of South Mountain
September 16-17
Battle of Antietam

Commanded by Colonel William S. Clark

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

September 17 – October 27 At Pleasant Valley, Md.
October 27-
November 17
Movement to Falmouth, Va.
November 15 Warrenton, Sulphur Springs
December 12-15
Battle of Fredericksburg
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
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
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
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.”
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 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