New Hampshire Governor Nathaniel Berry established the band as part of the Third New Hampshire Regiment on July 31, 1861, by an executive order to Gustavus W. Ingalls of Concord. The nucleus of the band's 24 members came from a cornet band organized in 1858 under D. Arthur Brown in Fisherville, now known as Penacook or Ward I of the City of Concord. Ingalls himself was a violinist, an associate for many years with A. Prescott and Co. of Concord (makers of organs and pianos) and, until the war, leader of the Concord Brass Band.

Upon its formation, the Third Regiment Band was sent promptly to participate in the siege of Charleston Harbor, South Carolina, but did not remain long. Following a War Department order discontinuing all but brigade bands in 1862, Ingalls and his musicians had to return to New Hampshire. In 1863, however, Ingalls was able to reorganize most of his original bandsmand and return to South Carolina as director of what became known as the Hilton Head Post Band, because the players' salaries were derived from the mail fund. Band members also performed extra-musical duties in the hospital corps, attending to the sick, the wounded, and the dead.

Like his short-lived predecessor, the band gained an excellent reputation. It was therefore the one honored to play patriotic tunes as well as the national anthem during a nationally symbolic flag-raising ceremony on April 14, 1865, celebrating the recapture of Fort Sumter at the war's conclusion.

Music books used by the band during the war remain in the Library of Congress, in the New Hampshire Historical Society in Concord, and in the New Hampshire Antiquarin Society in Hopkinton. They are recognized by knowledgeable researchers to contain some of the finest band arrangements of popular mid-19th century music, and they therefore have been used repeatedly in recent period instrument recordings of the repertoire.