Organized at Hartford May 21, 1861. Left State for Washington, D.C., June 10. Attached to Abercrombie's 6th Brigade, 2nd Division, Dept. of Pennsylvania, to August, 1861. 2nd Brigade, Banks' Division, Army Potomac, to December, 1861. Defenses of Washington to January, 1862.
SERVICE.--Duty at Chambersburg, Pa., and at Hagerstown, Md., till July 4, 1861, and at Williamsport till August 16. At Frederick, Md., till September 5. Moved to Darnestown September 5, thence to Fort Richardson. Defenses of Washington, D.C., and duty there till January, 1862. Designation of regiment changed to 1st Conn. Heavy Artillery January 2, 1862. (See 1st Heavy Artillery.)