The regiment was mustered into Federal service on October 15, 1861, at St. Albans, Vermont under Colonel Nathan Lord, Jr., the son of the Dartmouth College president Nathan Lord. It was engaged in, or present at, Warwick Creek, Lee's Mill, Williamsburg, Golding's Farm, Savage's Station and White Oak Swamp during the Peninsula Campaign; Crampton's Gap and Antietam during the 1862 Maryland Campaign; Battle of Fredericksburg, Marye's Heights, Salem Church, and Banks' Ford; Gettysburg and Funkstown during the Gettysburg Campaign; Gainesville and Rappahannock Station; the Wilderness, Spotsylvania, Cold Harbor, Petersburg, Wilmington and Weldon Railroad, and Reams' Station during the Overland Campaign; Fort Stevens; Charlestown, Third Battle of Winchester, Fisher's Hill, and Cedar Creek during the Shenandoah Valley campaign; the Siege of Petersburg, and Sayler's Creek.