21st Massachusetts

21st Massachusetts
Frank Leslie’s Illustrated Newspaper / Photo Courtesy of U.S. Army · Public domain · source
Unit name	21st Massachusetts Volunteer Infantry
Dates	October 1861–June 1865
Allegiance	Union (American Civil War)
Branch	Union Army
Type	Infantry
Size	Regiment
Garrison	Boston, Massachusetts
Battles	Siege of Suffolk, Siege of Petersburg, Battle of Antietam, Battle of Fredericksburg, Siege of Suffolk (April–May 1863), Appomattox Campaign
Notable commanders	Colonel William S. Clark (Massachusetts politician), Colonel George H. Gordon

21st Massachusetts was an infantry regiment raised in Massachusetts for service in the American Civil War. Organized in Boston, Massachusetts in late 1861, the regiment served in multiple theaters including Maryland Campaign (1862), operations in Virginia, and the final assaults around Petersburg, Virginia. Throughout its service the unit was assigned to various corps and divisions of the Army of the Potomac and the Department of the South, taking part in major campaigns, sieges, and expeditions until mustering out in 1865.

Formation and Early History

The regiment was recruited during the volunteer drive following President Abraham Lincoln's call for troops and assembled in Boston, Massachusetts, drawing companies from counties including Worcester County, Massachusetts, Suffolk County, Massachusetts, and Essex County, Massachusetts. Early organization placed it under state authorities coordinated with the Massachusetts adjutant general and the War Department (United States), echoing mobilization patterns seen in regiments such as the 54th Massachusetts Regiment and 20th Massachusetts Volunteer Infantry. Initial training and camp duty occurred near Camp Meigs (Readville), with officers receiving commissions under the governor of Massachusetts and coordinating with federal quartermasters and ordnance officers for arms and equipment.

Organization and Service in the American Civil War

After muster, the regiment was attached at various times to brigades and divisions within the Army of the Potomac, including assignments under commanders associated with the V Corps (Union Army), VII Corps (Union Army), and transient duty with the Department of North Carolina and the Department of Virginia and North Carolina. Service obligations included picket duty, fortification construction, and participation in expeditions such as operations against coastal positions and railroad lines supporting the Richmond and Petersburg Campaign. The 21st Massachusetts frequently coordinated with units including the 1st Massachusetts Cavalry, 2nd Massachusetts Volunteer Infantry, and Massachusetts artillery batteries in combined operations and joint maneuvers.

Major Engagements and Campaigns

The regiment saw action during the Maryland Campaign (1862), notably in the aftermath of the Battle of Antietam, and was engaged during the Battle of Fredericksburg operations. It participated in the prolonged Siege of Suffolk and later was involved in operations contributing to the Siege of Petersburg and the final Appomattox Campaign that culminated in the surrender terms associated with Appomattox Court House. During coastal operations the regiment supported expeditions tied to the Burnside Expedition and raids against rail lines such as the Norfolk and Petersburg Railroad. Engagements put the regiment in proximity to major actions like the Battle of Chancellorsville maneuverings, the Overland Campaign probes, and sieges where coordination with siege engineers and artillery under generals from the Army of the Potomac was critical.

Commanders and Notable Personnel

Commanding officers included field leaders commissioned by Massachusetts and recognized within the federal structure; among them were figures with prior militia experience and links to state politics and civic institutions. Officers served alongside contemporaries from units such as the 1st Massachusetts Infantry (Reorganized), and occasionally coordinated with higher-level commanders from formations under generals like George B. McClellan, Ambrose Burnside, and Ulysses S. Grant. Notable enlisted men and junior officers went on to postwar roles in Massachusetts politics, veterans' organizations such as the Grand Army of the Republic, and civic institutions including veterans' relief efforts and memorial commissions in cities like Boston, Massachusetts and Springfield, Massachusetts.

Casualties and Strength

Muster rolls and returns reflected the attrition common to infantry regiments engaged in sustained campaigns: killed and mortally wounded in action, wounded and returned to duty, missing and captured, and deaths from disease were recorded in line with Union Army reporting. The regiment's numbers fluctuated due to enlistment expirations, recruitment of replacements, and consolidations with other Massachusetts units when necessary. Casualty figures mirrored patterns seen across Union regiments during sieges and assaults, where disease such as dysentery and typhoid in camp settings claimed many lives alongside combat losses reported after engagements like Antietam and Fredericksburg.

Postwar Legacy and Commemoration

After mustering out in 1865, veterans of the regiment participated in Grand Army of the Republic posts, Memorial Day commemorations, and local veterans' reunions in Massachusetts towns. Monuments and markers honoring service members were erected at battlefields and in municipal cemeteries, often in concert with state-level Massachusetts Soldiers' and Sailors' Monument initiatives and battlefield preservation efforts at sites such as Antietam National Battlefield and Petersburg National Battlefield. Regimental histories, veterans' memoirs, and rosters were later used by historians and archivists in institutions like the Massachusetts Historical Society and the Library of Congress to document unit service, contributing to Civil War scholarship and public memory.

Category:Units and formations of the Union Army from Massachusetts Category:1861 establishments in Massachusetts Category:Military units and formations established in 1861 Category:Military units and formations disestablished in 1865