Organized at Portland and mustered in October 4, 1861. Left State for Baltimore, Md., October 6. Attached to Dix's Division to November, 1861. Railroad Brigade, Army Potomac, to April, 1862. 1st Brigade, Williams' Division, Dept. of the Shenandoah, to June, 1862. 1st Brigade, 1st Division, 2nd Army Corps, Army of Virginia, to September, 1862. 1st Brigade, 1st Division, 12th Army Corps, Army of the Potomac, to April, 1863. Headquarters 12th Army Corps, Armies of the Potomac and Cumberland, to November, 1863.

SERVICE.-Duty at Baltimore, Md., till November 4, 1861. At Relay House till November 27, and at Baltimore till February 27, 1862. Guard duty by detachments along Baltimore & Ohio Railroad between Martinsburg and Charleston, W. Va., till May. Company "D" at Harper's Ferry till May 24, then moved to Winchester. Company "F" at Harper's Ferry till May 9, then moved to Winchester. Company "H" at Duffield's till May 24, then moved to Winchester. Company "K" at Kearneysville till May 24, then moved to Winchester. Company "C" at Van Obeiseville till May 9, then moved to Winchester. Company "A" at Opequan Bridge till May 24, then moved to Winchester. Company "B" at Martinsburg till May 24, then moved to Winchester. Company "E" at Halltown till May 9, then moved to Winchester. Companies "G" and "I" at Charleston till May 9, then moved to Winchester. All Companies at their stations from March 28. Operations in Shenandoah Valley May 15-June 17. Middletown May 24. Winchester May 25. Retreat to Williamsport May 25-27. Reconnoissance toward Martinsburg May 28. Reconnoissance to Luray C. H. June 29-30. Battle of Cedar Mountain August 9. Pope's Campaign in Northern Virginia August 16-September 2. Guarding trains during Bull Run Battles. Battle of Antietam, Md., September 16-17. Duty at Berlin, Md., October 3-December 10. March to Fairfax Station December 10-14, and duty there till January 19, 1863. March to Stafford C. H. January 19-23, and duty there till April 27. Ordered to rear for muster out April 27. Three-year men formed into a Battalion of three Companies and assigned to duty at Headquarters 12th Army Corps April 26. Old members mustered out May 8, 1863. Chancellorsville Campaign April 27-May 6. Battle of Chancellorsville May 1-5. Gettysburg (Pa.) Campaign June 12-July 24. Battle of Gettysburg July 1-8. Along the Rapidan August 1-September 24. Moved to Nashville, Tenn., September 24-October 2; to Munfreesboro, Tenn., October 5, thence to Shelbyville and Wartrace. Reopening Tennessee River October 26-29. Provost duty at Headquarters 12th Corps till November. Transferred to 29th Maine Infantry November 1, 1863.

Regiment lost during service 8 Officers and 74 Enlisted men killed and mortally wounded and 1 Officer and 53 Enlisted men by disease. Total 136.