20th Massachusetts Infantry

Organized at Readville August 29 to September 4, 1861. Left State for Washington, D.C., September 4. Attached to Lander's Brigade, Division of the Potomac, to October, 1861. Lander's Brigade, Stone's (Sedgwick's) Division, Army of the Potomac, to March, 1862. 3rd Brigade, 2nd Division, 2nd Army Corps, Army of the Potomac, to March, 1864. 1st Brigade, 2nd Division, 2nd Army Corps, to July, 1865.

SERVICE.--Moved to Poolesville, Md., September 12-15, 1861. Guard duty along Upper Potomac till December. Operations on the Potomac October 21-24. Action at Ball's Bluff October 21. Near Edwards' Ferry October 22. Moved to Muddy Branch December 4, and duty there till March 12, 1862. Moved to Harper's Ferry, thence to Charlestown and Berryville, March 12-15. Ordered to Washington, D.C., March 24, and to the Peninsula March 27. Siege of Yorktown April 5-May 4. West Point May 7-8. Battle of Fair Oaks, Seven Pines, May 31-June 1. Seven days before Richmond June 25-July 1. Oak Grove, near Fair Oaks, June 25. Peach Orchard and Savage Station July 29. White Oak Swamp and Glendale June 30. Malvern Hill July 1 and August 5. At Harrison's Landing till August 15. Movement to Alexandria August 15-28, thence march to Fairfax C. H. August 28-31. Cover retreat of Pope's army from Bull Run August 31-September 1. Maryland Campaign September-October. South Mountain, Md., September 14 (Reserve). Battle of Antietam September 16-17. Moved to Harper's Ferry September 22, and duty there till October 30. Reconnoissance to Charlestown October 16-17. Advance up Loudon Valley and movement to Falmouth, Va., October 30-November 17. Battles of Fredericksburg December 11-15. (Forlorn hope to cross Rappahannock December 11.) Duty at Falmouth till April. Chancellorsville Campaign April 27-May 6. Maryes Heights, Fredericksburg, May 3. Salem Heights May 3-4. Gettysburg (Pa.) Campaign June 11-July 24. Battle of Gettysburg July 2-4. Advance from the Rappahannock to the Rapidan September 13-17. Bristoe Campaign October 9-22. Bristoe Station October 14, Advance to line of the Rappahannock November 7-8. Mine Run Campaign November 26-December 2. Demonstration on the Rapidan February 6-7, 1864. At Stevensburg till May. Campaign from the Rapidan to the James May-June. Battles of the Wilderness May 5-7. Laurel Hill May 8. Spottsylvania May 8-12. Po River May 10. Spottsylvania C. H. May 12-21. Assault on the Salient May 12. North Anna River May 23-26. Line of the Pamunkey May 26-28. Totopotomoy May 28-31. Cold Harbor June 1-12. Before Petersburg June 16-18. Siege of Petersburg June 16, 1864, to April 2, 1865. Jerusalem Plank Road June 22-23, 1864. Demonstration north of the James July 27-29. Deep Bottom July 27-28. Strawberry Plains, Deep Bottom, August 14-18. Ream's Station August 25. Boydton Plank Road, Hatcher's Run, October 27-28. Dabney's Mills, Hatcher's Run, February 5-7, 1865. Watkins' House March 25. Appomattox Campaign March 28-April 9. Crow's House March 31. Fall of Petersburg April 2. Sailor's Creek April 6. High Bridge and Farmville April 7. Appomattox C. H. April 9. Surrender of Lee and his army. At Burkesville till May 2. March to Washington, D.C., May 2-15. Grand Review May 23. Duty at Washington till July 15. Mustered out July 16 and discharged July 28, 1865.

Regiment lost during service 17 Officers and 243 Enlisted men killed and mortally wounded and 1 Officer and 148 Enlisted men by disease, Total 409.

SOURCE: Frederick H. Dyer, A Compendium Of The War Of The Rebellion, Part 3, p. 1254-5