The 21st Regiment, Connecticut Infantry was organized in August of 1862 at Norwich, New London County, Connecticut and mustered in on the 5th of September. This regiment was mustered out of service June 16, 1865.
The regiment lost 5 Officers and 55 Enlisted men killed and mortally wounded and 1 Officer and 114 Enlisted men by disease. Total 175.
Organized at Norwich September 5, 1862. Left State for Washington, D.C., September 11. Attached to 2nd Brigade, 3rd Division, 9th Army Corps, Army of the Potomac, to January, 1863. 3rd Brigade, 3rd Division, 9th Army Corps, to April, 1863. 3rd Brigade, 2nd Division, 7th Army Corps, Dept. of Virginia, to July, 1863. 3rd Brigade, Getty's Division, Portsmouth, Va., Dept. of Virginia and North Carolina, to October, 1863. Heckman's Command, Newport News, Va., Dept. Virginia and North Carolina, to February, 1864. Defenses of Newberne, N. C., Dept. Virginia and North Carolina, to March, 1864. Sub-District of the Pamlico, N. C., Dept. Virginia and North Carolina, to May, 1864. 3rd Brigade, 1st Division, 18th Army Corps, Dept. of Virginia and North Carolina, to December, 1864. 3rd Brigade, 3rd Division, 24th Army Corps, Dept. of Virginia, to June, 1865.
Duty at Arlington Heights, Va., Defenses of Washington, D.C., November, 1862. March to Falmouth, Va., November 7-19. Battle of Fredericksburg, Va., December 12-15. Burnside's 2nd Campaign, "Mud March," January 20-24, 1863. Moved to Newport News, Va., February 6-9, thence to Suffolk, Va., March 13. Siege of Suffolk April 12-May 4. Chuckatuck and Reed's Ferry, Nansemond River, May 3. Siege of Suffolk raised May 4. Reconnaissance to Chickahominy June 9-16. Moved to Portsmouth, Va., June 16. Provost and guard duty at Portsmouth and Norfolk November 10. Moved to Newport News November 10, and duty there February, 1864. Expedition up James River to Fort Powhatan January 24-25. Smithfield February 1. Moved to Morehead City, N. C., February 3, thence to Newberne February 12, and duty there, at Plymouth and at Washington, N. C., April. Near Blount's Creek April 5. Moved to Portsmouth, Va., April 28. Butler's operations on South Side of the James River and against Petersburg and Richmond May 10-28. Swift Creek, or Arrow field Church, May 10. Operations against Fort Darling May 12-16. Battle of Drewry's Bluff May 14-16. At Bermuda Hundred May 17-27. Moved to White House, thence to Cold Harbor May 27-31. Battles about Cold Harbor June 1-12. Before Petersburg June 15-18. Siege operations against Petersburg and Richmond June 16, 1864, to April 2, 1865. Hare's Hill June 24-28, 1864. In trenches at Bermuda Hundred August 25-September 27, 1864. Chaffin's Farm, New Market Heights, September 28-30. Fair Oaks October 27-28. Duty in trenches before Richmond March, 1865. Expedition to Fredericksburg March 5-8, and up the Potomac River March 11-13. Moved to White House March 13-18, thence to Signal Hill, before Richmond, March 24-26. Occupation of Richmond April 3. Moved to Columbia April 28, and duty there June. Mustered out June 16, 1865.
The roster of the 21st Infantry Regiment contains 1549 names.