Edward G. LongacrE, "Butterfield, Daniel," American National Biography Online, February 2000, http://www.anb.org/articles/05/05-00111.html.
Butterfield's rapid rise in the volunteer service and his regular army appointments cannot be reconciled with his limited talent as a field commander. Family prominence, high rank in the militia, and political connections appear to have been responsible. His managerial and organizational talents served him well as a staff officer, although his officiousness and his sometimes abrasive personality weakened his usefulness as a liaison between army headquarters and subordinate commanders. Despite his prominent position in the Union hierarchy, despite serving in important campaigns in the two major theaters of operations, and despite winning a Medal of Honor, he is remembered chiefly--but inaccurately--as the composer of "Taps."